Cereal_grains_for_the_food_and_beverage_industries_2075944_z_lib

318 Cereal grains for the food and beverage industries

L ×800 100 um

Fig. 9.4 Polyhedron starch cells of proso millet using, SEM Hitachi TM-1000,
magnification = ×800. Reprinted from Zarnkow et al., 2007, with permission from

the Journal of the Institute of Brewing.

electron microscopy (SEM) reveals that many large granules show indenta-
tions on their surface due to the dense packaging of the endosperm. Lorenz
(1977) and Kumari and Thayumanavan (1998) determined that small protein
bodies are attached to the starch granules. The protein bodies are concen-
trated in the peripheral cells of the endosperm, becoming more scattered
and less frequent towards the inside. Jones et al. (1970) also reported similar
results regarding the protein composition of proso millet. They observed
that protein in proso millet consisted mainly of globular bodies measuring
up to 2.5 μm in diameter. In the outer endosperm cells, some of the globular
proteins were embedded in an amorphous matrix protein; and only in the
inner endosperm could a small amount of matrix protein be found. The
protein bodies determined in this study were mainly prolamines.

9.2 Proso millet carbohydrate composition and properties

As proso millet consists of approximately 69.8 % carbohydrates, it can be
classified as a carbohydrate-rich food (Parameswaran and Sadasivam, 1994).
The carbohydrates of proso millet consist of starch, soluble sugars, pento-
sans, cellulose and hemicellulose (Serna-Saldivar and Rooney, 1995).

9.2.1 Starch
Starch is the most abundant carbohydrate in proso millet, contributing
52.1–68.2 % of the total carbohydrate content (Casey and Lorenz, 1977;

© Woodhead Publishing Limited, 2013

Millet 319

Hulse et al., 1980; Yanez and Walker, 1986; Parameswaran and Sadasivam,
1994). It is composed of the two polymers amylopectin and amylose and
occurs in granules in the endosperm. Each amylopectin molecule contains
up to two million glucose residues in a compact structure (Ring and Parker,
2001). The molecules are aligned in circles of increasing radii inside the
starch granule. As the length of the radii increases, molecules with a greater
degree of branching are required to fill up the space and consequently
concentric regions of alternating amorphous and crystalline structures are
formed. Some properties of the structural organization of starch granules
are discussed below.

Although starch granules are complex macromolecules, it is widely
accepted that it is the amylopectin polymer that is predominantly respon-
sible for granule crystallinity (Gallant et al., 1997). The percentage of amy-
lopectin in waxy types of proso millet is 99–100 % of the total starch content
while the percentage in normal types ranges from approximately 67.2 to
73.7 % (Yanez and Walker, 1986; Serna-Saldivar and Rooney, 1995). In
normal types of proso millet, it has been determined that amylose makes
up from 27.2 to 32.6 % of the total starch content (Fuwa et al., 1981; Yanez
and Walker, 1986; Yanez et al., 1991), but an additional 0–6 % amylose
content has also been reported by other authors (Hulse et al., 1980; Fuwa
et al., 1981). Overall, it can be concluded that these different results for the
starch content as well as the ratio of amylose to amylopectin may be caused
by the use of a variety of methods of extraction, but they mainly correspond
to the different varieties of proso millet and the conditions in which the
grain samples were grown.

Little data has been reported on the functional characteristics of proso
millet starch. The gelatinization temperature reflects the degree to which
the molecules in the starch granules are arranged in an orderly fashion, with
higher gelatinization temperatures indicating a higher degree of association
(Lorenz and Hinze, 1976). Fuwa et al. (1981) considered the starch gelati-
nization temperature of proso millet starch to be between 67 and 74 °C,
whereas Yanez and Walker (1986) determined it to be between 76 and 77 °C
(by Kofler Hot Stage). In contrast to these results, Lorenz and Hinze (1976)
measured gelatinization temperatures of between 60 and 64 °C. Kumari and
Thayumanavan (1998) determined a positive correlation between the
amylose content and a gelatinization temperature of approximately 76 °C.
To assess the degree of disintegration of gelatinized granules, starch can be
cooked at 95 °C and the drop in starch paste viscosity relative to peak vis-
cosity measured, which gives an indication of the extent to which the starch
granules have degraded (Mazurs et al., 1957). Proso millet showed a higher
degree of disintegration than other millets (Kumari and Thayumanavan,
1998). The viscous cooked starch agglutinates when it is cooled to tempera-
tures of around 50 °C.

The viscosity of the starch generally reflects the degree of retrograda-
tion of amylose (Mazurs et al., 1957), with high viscosity indicating a high

© Woodhead Publishing Limited, 2013

320 Cereal grains for the food and beverage industries

degree of retrogradation and the formation of resistant starch. The viscos-
ity of aqueous proso starch suspensions (with an average starch content of
10 %) of proso millet and other millets were measured and a positive cor-
relation between cold paste viscosity and amylose content could be seen.
The value for proso millet was reported to be 850 Brabender units, which
was the lowest of all reported values, reflecting the fact that proso millet
had the lowest amylose content (Kumari and Thayumanavan, 1998).
Studies on different rice starch suspensions (rice flour content 10 %) made
from different varieties of rice showed similar cold paste viscosity values
(Brites et al., 2004). The assays of Lorenz and Hinze (1976) showed that
the cold paste viscosity of proso millet (except for one variety), obtained
on cooling to 35 °C and holding the paste for 60 min, was higher than that
of wheat.

Proso millet measured at 60 °C and 70 °C demonstrated a higher resis-
tance to swelling (i.e. lower swelling power) than wheat and rye (Lorenz
and Hinze, 1976), due to bonding forces within the starch granule (Leach
et al., 1959). The size of the starch granules and the amylose content also
affect the swelling power. The higher the amylose content, the lower the
swelling power and the smaller the gel strength for the same starch concen-
tration. However, to a certain extent, the reducing effect that the high
amylose content of proso millet has on the swelling power is counteracted
by the larger size of the starch granules (Yeh and Li, 2001; Singh et al., 2003).
In short, it can be said that starch granules of proso millet have high amylose
content and a strongly bonded micellar structure.

9.2.2 Resistant starch
Resistant starch (RS) is defined as the sum of starch and degradation prod-
ucts of starch not absorbed in the small intestine of healthy individuals
(Asp et al., 1983). This includes unfermented faecal starch, as well as the
fraction which is fermented in the large intestine. Three main types of RS
have been identified: physically enclosed starch (type 1), ungelatinized
granules (type 2) and retrograded amylose (type 3) (Englyst et al., 1992).
The occurrence of RS in foods may have significant positive health implica-
tions as they can act in a similar way to fibre (Cronin and Shaw, 1988). In
proso millet with an absolute amylose content of 17.2 % (dry matter), the
RS level was 0.4 % w/w on a dry weigh basis. This is a relatively high value
when compared to rice, for example, which has 0.2 % w/w dry basis (Kumari
and Thayumanavan, 1997). Modification of native starch in proso millet by
autoclaving and cooling to obtain a certain degree of retrogradation
increased the RS content to 8.5 % w/w dry basis. RS in native and treated
millet type starches were positively correlated with the total amylose
content (Kumari and Thayumanavan, 1997). In vivo experiments on the
digestibility of native RS of millets and the rice variety oryza sativa were

© Woodhead Publishing Limited, 2013

Millet 321

performed in rats. The level of digestibility of proso millet (50 %) was sig-
nificantly higher than that of the other millets but still lower than that of
the rice variety (59.29 %) (Kumari and Thayumanavan, 1997). Further-
more, a large decrease in digestibility was observed when feeding the rats
with proso millet starch treated to increase its RS levels (39.9 % for proso
millet). However, proso millet had the greatest beneficial effects on health
of all the millets assayed. Reductions in blood glucose, serum cholesterol
and serum triglyceride levels were noted in rats fed with native starch as
well as treated starch of proso millet when compared to a rice diet (Kumari
and Thayumanavan, 1997). Moreover, its hypoglycaemic and hypolipidae-
mic attributes can be increased significantly by using suitable processing
parameters.

9.2.3 Dietary fibre
Dietary fibre (DF) is defined as ‘the edible parts of plants or analogous
carbohydrates that are resistant to digestion and absorption in the human
small intestine with complete or partial fermentation in the large intestine’.
It includes polysaccharides, oligosaccharides, lignin and associated plant
substances. Dietary fibres promote beneficial physiological effects including
laxation and/or blood cholesterol and glucose attenuation (AACC, 2001).
Dietary fibre fortification to counteract the effects of an unbalanced diet
can also have a negative effect as dietary fibre binds minerals.

According to Ferriola and Stone (1998), the content of DF in proso millet
ranges between 8.9 and 12.5 %. Proso millet contains 0.4 % hemicellulose
and 2.7 % cellulose, both of which are considered DF. The hemicellulose is
mainly composed of glucose, arabinose, uronic acid and xylose units (Serna-
Saldivar and Rooney, 1995).

9.2.4 Saccharides
Investigating the saccharide composition of eight samples of proso millet
by extraction with 70 % ethanol solution, Becker and Lorenz (1978) deter-
mined only traces of the monosaccharides glucose, fructose and galactose.
The disaccharide content was primarily sucrose at a proportion of 0.5–0.9 %
of the total dry weight, which is comparable to other cereal grains (Becker
et al., 1977; Becker and Lorenz, 1978). Raffinose was the next abundant
sugar and occurred at levels 0.04–0.10 % corresponding to about 1/10 of the
amounts normally found in mature kernels of wheat, rye and triticale
(Becker et al., 1977; Becker and Lorenz, 1978). Myo-inositol (which is not
a carbohydrate by definition as it belongs to the chemical class of cyclitols
– IUPAC, 1994) was found in minor quantities at up to 0.01 %. Neither
maltose nor maltotriose has been detected in proso millet (Becker and
Lorenz, 1978).

© Woodhead Publishing Limited, 2013

322 Cereal grains for the food and beverage industries

9.3 Proso millet protein composition and properties

Proso millet, like other millets crops, does not contain gluten-forming pro-
teins and its gluten-free status renders proso millet suitable for people with
coeliac disease (CD) and other intolerances to wheat who cannot eat prod-
ucts from gluten-containing cereals.

Storage proteins (SP) account for about 50 % of the total protein content
of mature cereal grains. SP are mainly generated during seed production
and serve as a nitrogen source during germination. According to Osborne
(1907), the proteins in grains can be divided into four groups based on their
solubility: (i) albumins (soluble in distilled water and dilute buffers at
neutral pH); (ii) globulins (soluble in salt solutions but insoluble in distilled
water); (iii) glutelins (soluble in dilute acid or alkali solutions); and (iv)
prolamins (soluble in aqueous alcohols of 70–90 %) (Bewley and Black,
1985).

According to Serna-Saldivar and Rooney (1995) and Jones et al. (1970),
prolamin constitutes the major protein fraction in proso millet (25.1–36.9 %
of total protein). SDS-PAGE showed that true prolamin from proso millet
had a major band corresponding to a molecular mass of 24 kDa together
with two minor bands of 14 and 17 kDa. The major polypeptides in the
prolamin-like fraction were similar to prolamin, but many minor bands
were found in higher molecular mass regions of more than 30 kDa (Kohama
et al., 1999).

9.3.1 Amino acid composition
The quality of a protein is primarily a function of its essential amino acid
composition. Essential amino acids are those which cannot be synthesized
by the human body, whereas the non-essential amino acids can be synthe-
sized by the human body if the necessary chemical components are avail-
able. The protein content of proso millet utricle is comparable with that
of maize, but varies widely from approximately 6 to 16 %. The content
is dependent on various parameters, such as the presence of water
and nutrients in the soil and the conditions during grain formation (Jones
et al., 1970b; Lorenz and Hinze, 1976; Lorenz, 1983; Ravindran, 1992;
Parameswaran and Sadasivam, 1994; Parameswaran and Thayumanavan,
1995; Kohama et al., 1999; Gabrovska et al., 2002; Kalinova and Moudry,
2006). The composition of amino acids in proso millet is shown in Table
9.2. It is comparable to those shown in a table by Sernar-Saldivar and
Rooney (1995).

9.3.2 Nutritional quality
Several methods are currently in use for evaluating protein quality. The
‘protein digestibility–corrected amino acid score (PDCAAS)’ has been
announced by the FAO/WHO as the preferred method for the evaluation

© Woodhead Publishing Limited, 2013

Millet 323

Table 9.2 Means, maximum values and minimum values for crude protein and
amino acids measured independently in a variety of studies. Amino acids in italics
are essential while the remaining amino acids are non-essential

Parameter Maximuma,b Minimuma,b Meansa,c

Essential 3.48 1.60 1.24–3.30
Lysine (Lys) 3.94 2.30 1.31–2.83
Histidine (His) 4.50 3.70 3.02–4.08
Threonine (Thr) 7.30 4.69 4.80–6.40
Valine (Val) 4.30 3.40 2.22–4.10
Methionine (Met) 5.81 4.22 3.91–5.34
Isoleucine (Ile) 14.70 12.52 13.00–14.00
Leucine (Leu) n. n. n. n.
Tryptophane (Trp) 6.82 5.62 1.33
Phenylalanine (Phe) 5.60–6.30
4.30 4.00
Non-essential 12.00 6.60 2.75–4.10
Arginin (Arg) 7.90 4.43 5.77–11.27
Aspartic acid (Asp) 25.40 21.94 4.91–7.60
Serine (Ser) 7.90 7.60 21.58–25.20
Glutamic acid (Glu) 1.10 0.90 7.19–7.80
Proline (Pro) 4.73 2.80 1.00–1.69
Cysteine (Cys) 12.40 9.68 2.13–4.48
Glycine (Gly) 4.70 4.30 10.27–11.70
Alanine (Ala) 16.30 12.12 3.64–4.50
Tyrosine (Tyr) 9.88–14.40
Protein d

aAmino acid data is expressed in g 100 g protein.
bFrom Ravindran (1992), Kalinova and Moudry (2006).
cFrom Ravindran (1992), Kasaoka et al. (1999), Kalinova and Moudry (2006).
dProtein content is expressed in % of dry weight.

of protein quality based on the amino acid requirements of humans. The
method is based on comparison of the concentration of the first limiting
essential amino acid in the test protein with the concentration of that amino
acid in a reference (scoring) pattern. This scoring pattern is derived
from the essential amino acid requirements of preschool-aged children
(Schaafsma, 2000). The PDCAAS can be calculated from the following
formula:

PDCAAS (%) = true faecal protein digestibility in % × amino
acid score (or the lowest amino acid ratio)

PDCAAS values higher than 100 % are not accepted as such but are
truncated to 100 %. Although the principle of the PDCAAS method has
been widely accepted, critical questions have been raised in the scientific
community about a number of issues.These questions relate to: (i) the valid-
ity of the preschool-age child amino acid requirement values; (ii) the validity
of correction for faecal instead of ileal digestibility; and (iii) the truncation

© Woodhead Publishing Limited, 2013

324 Cereal grains for the food and beverage industries

Table 9.3 Recommended amino acid by FAO/WHO/UNU

Amino acids Maximuma Children Amino acid score (%)
(2–5 years)a,b

Essential 3.48 5.80 60.00
Lysine (Lys) 3.94 – –
Histidine (His) 4.50
Threonine (Thr) 7.30 3.40 132.35
Valine (Val) 4.30 3.50 208.57
Methionine (Met) 5.81 2.50c 239.60
Isoleucine (Ile) 14.70 2.80 207.50
Leucine (Leu) 1.33 6.60 222.73
Tryptophane (Trp) 6.82 1.10 120.91
Phenylalanine (Phe) 6.30d 182.86
4.70
Non-essential 1.69
Tyrosine (Tyr)
Cysteine (Cys)

aAmino acid data is expressed in g 100 g protein.
bFAO/WHO/UNU (1985).
cMethionine + cysteine.
dPhenylalanine + tyrosine.

Note: Data on the essential amino acid content of proso millet were taken from Table 9.2.

Tyrosine and cysteine are non-essential amino acids, but they can fulfil the requirement for

phenylalanine and methionine, respectively.

of PDCAAS values to 100 % (Schaafsma, 2000).A comparison of the values
recommended by the FAO/WHO/UNU (1985) and the proso millet amino
acid composition values (Table 9.2) is shown in Tables 9.3 and 9.4.The amino
acid score (AAS) is determined by using the formula:

AAS = amount of essential amino acid in proso millet in
g/FAO/WHO/UNU-recommended amino acid value for
pre-school children in g

Proso millet protein, like other grain proteins (Serna-Saldivar and
Rooney, 1995) is obviously primarily deficient in the essential amino acid
lysine as shown in Tables 9.3 and 9.4. This is largely due to the fact that
usually the albumin–globulin and glutelin fractions, which are rich in lysine
(Serna-Saldivar and Rooney, 1995), are poorly represented in proso millet.
Parameswaran and Sadasivam (1994) observed an increase in the lysine and
tryptophane levels during germination. The threonine and methionine
levels, however, are higher than in cereal grains (Resurreccion et al., 1979;
Gopalan et al., 1980). Ravindran (1992) estimated the in vitro digestibility
of proso millet flour by the multi-enzyme method of Hsu et al. (1977), modi-
fied by Salgo et al. (1985). The samples showed an average of 71.3 % for
raw and 88.6 % for cooked proso millet flour. According to Geervani and
Eggum (1989), who acquired a true digestibility of 99.3 % using rats, the
values obtained using the enzymatic method were under-estimates.

© Woodhead Publishing Limited, 2013

Millet 325

Table 9.4 Recommended amino acid by FAO/WHO/UNU

Amino acids Minimuma Children Amino acid score (%)
(2–5 years)a,b

Essential 1.24 5.80 21.38
Lysine (Lys) 1.31 – –
Histidine (His) 3.02
Threonine (Thr) 4.69 3.40 88.82
Valine (Val) 2.22 3.50 134.00
Methionine (Met) 3.91 2.50c 124.80
Isoleucine (Ile) 12.52 2.80 139.64
Leucine (Leu) 1.33 6.60 189.70
Tryptophane (Trp) 5.60 1.10 120.91
Phenylalanine (Phe) 6.30d 146.67
3.64
Non-essential 0.90
Tyrosine (Tyr)
Cysteine (Cys)

aAmino acid data is expressed in g 100 g protein.
bFAO/WHO/UNU (1985).
cMethionine + cysteine.
dPhenylalanine + tyrosine.

Note: Data for the essential amino acid content of proso millet were taken from Table 9.2.

Tyrosine and cysteine are not essential amino acids, but they can fulfill the requirement for

phenylalanine and methionine, respectively.

9.3.3 Enzymes
The numerous transformations occurring during food fermentation and, in
particular, those that take place during brewing and malting depend exclu-
sively on the action of enzymes. Proso millet itself contains a number of
enzymes, but most of them are present only in small amounts. Most of the
enzyme content of malt is produced during malting. Optimizing the mashing
conditions and, in particular, the enzyme activity will help to produce proso
millet malt wort that is comparable to barley malt wort. It represents
another important step on the way to producing a gluten-free beer from
proso millet.

α-amylase
α-amylase hydrolyses starch, glycogen and other 1,4-α-glucans working in
an endo-acting mechanism. Amylose is split into oligosaccharides of 6–7
glucose units.Amylopectin is cleaved in a non-specific manner, as α-amylase
is not specific for the 1,6-α-branching point (Belitz et al., 2009). A very low
α-amylase activity is measurable in ungerminated mature proso millet
seeds. Parvathy and Sadasivam (1982) germinated proso millet seeds by
placing them on a double layer of moistened filter paper in petri dishes and
kept them at 29 °C in the dark from one to eight days. After a two-day lag
period, the activity increased strongly, peaking on day five of germination.

© Woodhead Publishing Limited, 2013

326 Cereal grains for the food and beverage industries

Within three days, the activity almost decreased to the initial level. Zarnkow
et al. (2007) reported that α-amylase activity in proso millet malt is rela-
tively low compared to barley malt.

β-amylase
β-amylases are exo-hydrolases that release maltose from the non-reducing
end of α-1,4-linked poly- and oligoglucans until the first α-1,6-branching
point along the substrate molecule is encountered (Ziegler, 1999).Yamasaki
(2003) isolated β-amylase from germinating proso millet seeds. The molecu-
lar weight (Mr) of the monomeric enzyme was estimated to be 58 000 based
on its mobility on SDS–PAGE and gel filtration with TSKgel G4000SWXL.
The enzyme activity significantly increased during days one and four of
germination, as correspondingly did seed germination. The enzyme hydro-
lysed malto-oligosaccharides more readily as their degree of polymerization
increased. The levels of hydrolysis were highest for malto-oligosaccharides
larger than 13 glucose residues and were considerably lower for maltotriose.
Amylopectin and soluble starch were hydrolysed three times faster than
maltoheptose. Amylose, amylopectin and soluble starch were the most suit-
able substrates for the enzyme. Starch digestion was accelerated 2.5-fold
when β-amylase was added to a reaction mixture including α-amylase, pul-
lulanase and α-glucosidase. Thus, β-amylase should be considered a key
enzyme in starch degradation during the germination of millet seeds.
The optimum pH of the enzyme was found to be 5.5–6.0 which is 0.5–1.0
higher than Skovron and Lorenz (1979) hypothesized. It was stable with
pH in the range 3.5–9.0. The optimum temperature was found to be 55 °C.
A pre-incubation with 5 mM of metal ions at 37 °C for 30 min, Hg2+, Mn2+
and Cu2+ reduced the β-amylase activity by 80 % or more (Yamasaki, 2003).
However, it is difficult to compare enzyme activities as they vary between
single cultivars grown in slightly different locations (Skovron and Lorenz,
1979).

α-glucosidase
α-glucosidase in seeds may play an important role during seed respiration
and during the early stage of germination, as its activity to liberate glucose
from starch doubles after 24 h of germination (soaking) (Yamasaki et al.,
2005). On the other hand, some authors, including Swain and Dekker (1966)
and Nomura et al. (1969), claim that α-glucosidase is part of the non-
phosphorolytic pathway for the breakdown of starch, and plays a role in
seed germination by hydrolysing the oligosaccharides produced by α- and
β-amylases. Sun and Henson (1990), reported that barley seed α-glucosidase
can initiate the breakdown of raw starch granules and that this activity is
independent of the presence of α-amylase.

Yamasaki et al. (1996) isolated two forms of α-glucosidase (I and II)
from proso millet seeds using fractionation and preparative gel electro-
phoresis. The two enzymes showed identical Mr, calculated to be 85 000 on

© Woodhead Publishing Limited, 2013

Millet 327

SDS-PAGE and 93 000 on gel filtration. The optimum pH for the activity
of the two α-glucosidases was found to be 3.5, and they were stable in
pH ranges from 3.5 to 6.0 (I) and 3.5 to 5.5 (II), respectively. The optimal
temperature for the two α-glucosidases was found to be 60 °C. The two
enzymes hydrolysed malto-oligosaccharides and maltose at a similar rate.
α-glucosidase (II) weakly hydrolysed native starch from millet seeds.
α-glucosidase (I) activity was reduced up to and greater than 20 % after
incubation with Hg2+, Zn2+ and Cu2+, whereas α-glucosidase (II) activity was
not inhibited by Zn2+ and Cu2+. Yamasaki et al. (2005) also found that the
activity doubled after the proso millet seeds had been soaked in water for
24 h. The α-glucosidases showed a higher affinity for polysaccharides than
for maltose, even when polysaccharides were present at considerably lower
concentrations than maltose.

The Michaelis–Menten constant, Km, value for maltose is lower than
those of α-glucosidases from other plants, such as rice seed (Eksittikul
et al., 1993), buckwheat (Chiba et al., 1979), sugar beet (Matsui et al., 1978;
Yamasaki and Konno, 1991) and barley (Henson and Sun, 1995). The Km
value for malto-oligosaccharides decreased with an increase in the molecu-
lar weight of substrate. α-glucosidase may preferably hydrolyse oligosac-
charides liberated from starch by α-amylase to glucose without the preceding
action of β-amylase during the germination of millet seeds, although it has
been suggested that α-glucosidase needs the preceding action of α- and
β-amylases to play a role during the germination of plants (Swain and
Dekker, 1966; Nomura et al., 1969).

Cellulase and hemicellulase
Skovron and Lorenz (1979) measured cellulase and hemicellulase activity
in millet varieties. Only a few varieties showed no hemicellulase activity.

Protease
Little has been reported about protease activities in millets in the literature
to date. Skovron and Lorenz (1979) examined proteases from eight differ-
ent cultivars of proso millet extracted at different pH values. In all cases,
protease activity was higher in the pH 4.8 extract than in the pH 3.8 one.
The protease activity in rice is comparable to activity in proso millet (Lorenz
and Saunders, 1978).

Inhibitors
Protease inhibitors have been identified in most plants and are distributed
in the seeds, leaves and nuts (Liener and Kakade, 1980). These inhibitors
are usually heat-labile proteins that can bind to the active site of vertebrate
digestive enzymes with very high affinity. The presence of protease inhibi-
tors in seeds is not completely understood, but they are known to have
the following functions: (i) storage (in some cereals trypsin inhibitors can
contribute 5–10 % of water soluble proteins); (ii) control of endogenous

© Woodhead Publishing Limited, 2013

328 Cereal grains for the food and beverage industries

enzymes (some authors believe inhibitors control the activity of proteolytic
enzymes); and (iii) protection (protease inhibitors might inhibit the proteo-
lytic digestive enzymes of invading insects or pathogenic microflora)
(Bewley and Black, 1985). Ravindran (1992) made investigations of trypsin
and chymotrypsin inhibitory activities in proso millet using the method of
Kakade et al. (1969, 1970). The activities were measured as trypsin inhibi-
tory units (TIU) and chymotrypsin inhibitory units (CIU), expressed as
numbers of trypsin units (TU) and chymotrypsin units (CU) inhibited per
gram dry weight. A TU or CU is defined as the increase of 0.01 absorbance
units at 280 or 275 nm, respectively. High trypsin inhibition (732 ± 11.7 TIU)
compared to chymotrypsin inhibition (62 ± 6.6 CIU) was observed. On the
other hand, Chandrasekher et al. (1982) could not detect protease inhibition
while screening 13 varieties of proso millet.

Nagaraj and Pattabiraman (1985) purified an α-amylase inhibitor from
proso seeds, which is specific for human pancreatic amylase. The factor was
more effective by two orders of magnitude in its action on human pancre-
atic anylase than on human salivary amylase. This attribute makes the
inhibitor suitable for application in differentiating salivary and pancreatic
amylases in sera for diagnostic purposes. Chemical modification studies
revealed that amino and guanido groups are essential for the action of the
inhibitor. The molecular weight calculated based on its mobility during
SDS-PAGE was 14 000 which agreed well with the value of 13 000 using gel
chromatography. Pepsin was found to rapidly inactivate the inhibitor, and
complete abolition of amylase inhibitory activity was observed in 20–30 min.
Trypsin and chymotrypsin were relatively slow in this respect. It took 8 h
of interaction with these enzymes for the proso inhibitor to lose its activity
completely. Pronase was found to inactivate the inhibitor in 2 h.

Other studies showed the effect of the proso millet α-amylase inhibitor
against human and bovine enzymes. Weak activities were observed against
guinea pig, rat and dog amylases and there was no detectable activity
against cat, rabbit, chicken, equine and porcine enzymes (Kutty and
Pattabiraman, 1986). Moreover, investigations showed that heating and
processing,e.g.malting or exposure to human enzymes like pepsin,decreased
its biological action to an insignificant level (Anderson, 1985; Nagaraj and
Pattabiraman, 1985; Serna-Saldivar and Rooney, 1995).

9.3.4 Health-promoting properties
Nishizawa et al. (1989, 2002) described the effects of dietary protein
from proso millet on rats. Liver injury was induced in the rats by
D-galactosamine or carbon tetrachloride using serum enzyme activities as
indices. D-galactosamine provoked increases of serum activities of lactate
dehydrogenase, alanine aminotransferase and aspartate aminotransferase
which were drastically suppressed by a diet containing 20 % proso millet

© Woodhead Publishing Limited, 2013

Millet 329

protein for 14 days compared to those fed with a 20 % casein diet. Further-
more, proso millet protein was found to be more effective at lower dietary
protein levels than dietary gluten.Therefore, it may be concluded that proso
millet protein could be incorporated into the diet to prevent liver injury
(Nishizawa et al., 2002).

To investigate the effects of dietary protein on plasma cholesterol metab-
olism in rats, casein-based and soy protein isolate-based diets (SPI) were
compared to a proso millet protein diet supplemented with lysine and
threonine. The impacts on food intake and bodyweight gain, as well as the
concentrations of cholesterol and triglyceride in the rats’ plasma and liver,
were determined.The plasma cholesterol concentrations of the rats fed with
SPI were significantly lower than those of the rats receiving the casein diet.
Rats fed the proso millet protein diet showed significantly higher plasma
cholesterol concentrations than those fed the other two diets. Similarly, the
value of plasma HDL-cholesterol in the rats fed with millet protein was
also highest among three dietary groups. HDL-cholesterol is thought to be
inversely related to the risk of coronary heart disease (HD). Therefore, a
diet of proso millet protein supplemented with lysine and threonine might
favourably affect the cholesterol metabolism (Nishizawa et al., 1989).
However, further research needs to be done.

9.4 Other constituents of proso millet

Lipid, vitamins, mineral, and phenolic compounds also characterize the
millet kernel. While lipids are mainly concentrated in the germ, vitamins,
minerals and phenolic compounds are diversely distributed in the pericarp,
aleurone layer and germ.

9.4.1 Lipids
Lipids in cereal grains are relatively minor constituents (Serna-Saldivar
and Rooney, 1995). Total lipid contents from 4.1 to 9.0 % (dry weight
based) in whole grains of different varieties of proso millet have been
found using different extraction methods. Between 3.8 and 5.6 % were
assigned as free lipids (FL), 0.6–2.5 % as bound lipids (BL) and 0.9 % as
structural lipids (Lorenz and Hwang, 1986; Gabrovska et al., 2002). Lipid
composition analysis is essential to decipher the individual storage stabili-
ties and nutritional aspects of the different lipid components of proso
millets (Lorenz and Hwang, 1986). As most of the lipids are located in
the scutellum, lipid contents are significantly reduced when kernels are
decorticated and/or degermed (Serna-Saldivar and Rooney, 1995). Sridhar
and Lakshminarayana (1994) divided the lipids into three major classes:
(i) non-polar lipids (NL); (ii) glycolipids (GL); and (iii) phospholipids

© Woodhead Publishing Limited, 2013

330 Cereal grains for the food and beverage industries

Table 9.5 Constituents and lipid subclasses (% w/w) in proso millet and their cor-
responding fatty acid composition (% w/w)

Non-polar lipid sub-classes % of SC 16:0 18:0 18:1 18:2 18:3

Triacylglycerols 81.2 6.4 1 23.8 64.7 1.8
Diacylglycerols 2.9 36.5 12.1 13.8 33.1 3.8
Monoacylglycerols 1.1 –
Free fatty acids 4 –––– 2.8
Free sterols 7.8 11.9 3.2 22 59.9 –
Steryl esters 3 1.2
––––
Glycolipid sub-classes 12.5 11.1 2.2 22.2 62.4
Sterylglycosides 29.5
Esterified sterylglycosides –––––
Cerebrosides 2
Digalactosyldiglycerides 11.5 20.5 4.9 13.8 56.6 4
Monogalactosyldiglycerides 40.4
Monogalactosylmonoglycerides 23.4 7.6 13.3 52.5 3.2
4.1
Phospholipid sub-classes 26.8 4.5 14.3 49 5.4
Phosphatidic acid 1.5
Phosphatidylglycerol Traces 12.8 3.4 15.4 63.6 4.8
Phosphatidylethanolamine
Phosphatidylcholine 30 23.6 7.2 12.1 53.6 3.5
Lysophosphatidylcholine 36.8
Phosphatidylserine 22 40.2 10.2 12.8 31.5 5.3
Phosphatidylinositol 8.5 –––– –
Traces 4.5
20.7 4 23.3 47.5 6.2
21.4 3.5 20.6 48.3 5.7
23.8 3.8 17.3 49.4 5.4
34.3 5.3 8.6 46.4 –

––––

SC = sub-class.
Note: Figure before colon indicates the number of carbon atoms and the figure after colon the
number of double bonds in the fatty acid chain.

(PL). The NL constituted the major portion of total lipids ranging from
80 to 83 %, whereas the GL and PL contents varied from 6 to 14 % and
5 to 14 %, respectively. NL, GL and PL are further divided into sub-classes.
The contingents of the different lipid sub-classes as well as their fatty acid
composition are shown in Tables 9.5 and 9.6. The major components of
the lipids are triacylglycerols, whose esterified fatty acids are mainly lin-
oleic acids (18 :2) followed by oleic acid.

These results align with the observations done by Gabrovská et al. (2002)
and Lorenz and Hwang (1986). The high proportion of unsaturated fatty
acids causes a high sensitivity to lipid oxidation during storage, particularly
if the grain is milled. Bookwalter et al. (1987) demonstrated that the inac-
tivation of lipase by a 97 °C heat-treatment minimizes fat hydrolysis. On
the other hand, the composition of proso millet lipids can be assessed as
positive with regard to nutritional value because linoleic acid is essential
for humans as a precursor of arachidonic acid. Arachidonic acids are essen-
tial for the synthesis of prostaglandins. Two of them (thromboxan and
prostacyclin) have a preventive effect against cardio- and angiopathy
(Oelz, 1982).

© Woodhead Publishing Limited, 2013

Millet 331

Table 9.6 Contingents of lipid subclasses (% w/w) in proso millet and their cor-
responding fatty acid composition (% w/w)

Non-polar lipid sub-classes % of SC 20:0 20:4 22:0 22:1

Triacylglycerols 81.2 0.8 0.4 0.7 0.4
Diacylglycerols 2.9 – – 0.7 –
Monoacylglycerols 1.1 ––––
Free fatty acids 4 – – 0.2 –
Free sterols 7.8 ––––
Steryl esters 3 – 0.1 0.2 0.6

Glycolipid sub-classes 12.5 ––––
Sterylglycosides 29.5 – – 0.2 –
Esterified sterylglycosides ––––
Cerebrosides 2 ––––
Digalactosyldiglycerides 11.5 ––––
Monogalactosyldiglycerides 40.4 ––––
Monogalactosylmonoglycerides
4.1 ––––
Phospholipid sub-classes ––––
Phosphatidic acid 1.5 ––––
Phosphatidylglycerol traces ––––
Phosphatidylethanolamine 30 ––––
Phosphatidylcholine 36.8 ––––
Lysophosphatidylcholine 22 ––––
Phosphatidylserine
Phosphatidylinositol 8.5
traces

SC = sub-class.
Note: Figure before colon indicates the number of carbon atoms and the figure after colon the
number of double bonds in the fatty acid chain.

9.4.2 Minerals
Among functional food components, minerals play an essential role and
deficiencies in essential minerals are seen as a major nutritional problem
in the world today. Proso millet is an important source of minerals. The
pericarp, aleurone layer and germ are rich sources of ashes (Serna-Saldivar
and Rooney, 1995). Table 9.7 shows mineral contents measured in proso
millet as well as the recommended daily intake. Proso millet is a poor source
of Ca; K and P are the minerals found in greatest amounts. However, abun-
dance does not imply much about the nutritional value of minerals as
bioavailability is influenced by many other parameters.

Taking phytic acid as an example, the average amount of this mineral
found in proso millet is 0.61 g/100 g (dry weight basis), which is comparable
to that found in other cereals (Becker and Lorenz, 1978; Ravindran, 1991),
and it is the principal storage form of P in grains (67.3 % of the P in proso
millet). Non-ruminant animals lack the digestive enzyme phytase, which is
required to separate P from the phytate molecule (Ravindran, 1991); there-
fore the presence of P in this form highly affects the bioavailability of this

© Woodhead Publishing Limited, 2013

332 Cereal grains for the food and beverage industries

Table 9.7 Mineral composition of proso millet and the recommended daily intake

Minerals mg/100 g sample Recommended daily
(dry weight basis) intake (mg)a

Ash 1500.00–4200.00 –
Sodium 2.8–60.0 100–550
Potassium 400–2000
Calcium 235.0–370.0 220–1200
Magnesium 7.3–30.0
Phosphorus 24–400
Trace minerals 120.0–145.2 120–1250
Zinc 230.0–362.6
Iron 1.0–11.0
Manganese 1.72–11.00 0.5–20
Copper 4.20–20.00 0.6–5.0
0.2–1.5
0.8–19
0.83–4.00

aValues are those recommended by the German Nutrition Society (DGE) (2007) (http://
www.dge.de/modules.php?name=content&pa=showpage&pid=3&page=1) depending on age
groups, sex, and physiological condition.
Sources: Gabrovská et al. (2002), Ravindran (1991), Serna-Saldivar and Rooney (1995).

mineral in these species. Phytic acid is also a strong inhibitor of Fe absorp-
tion in both infants and adults, but its effect in infants seems to be modest
and it is perhaps most important in children recovering from infection. It
also has a minor effect on Ca and Mg absorption. Research reports that
only 43 % of the Ca in finger millets was retained by rats due to the adverse
effect of the high phytate content (Hurrell, 2003). Bioavailability can also
be affected by processing proso millet. Processing can have a positive
impact through the separation or partitioning of minerals (enrichment),
through the destruction of inhibitors or through promotion of the formation
of beneficial complex between food components and metal ions, thereby
enhancing their availability. However, the impact can also be negative if
enzymes that degrade inhibitors are deactivated or insoluble metal com-
pounds (e.g. oxidation, precipitation) are generated (Matzke, 1998).

9.4.3 Vitamins
Vitamins are important organic compounds which cannot be synthesized
by the human body (or cannot be synthesized in sufficient quantity); hence,
it is necessary to provide humans with adequate amounts of vitamins
through the diet. Vitamins are mainly divided into two groups: fat-soluble
vitamins, which include vitamin A (retinoids), vitamin D (calciferols),
vitamin E (tocopherols) and vitamin K (naphtochinones); and water-soluble
vitamins, which include vitamin B1 (thiamines), vitamin B2 (riboflavins),
niacin (nicotinic acid), vitamin B6 (pyridoxines), folic acid, pantothenic acid,
biotin, vitamin B12 (cyanocobalamines) and vitamin C (ascorbic acid). Proso

© Woodhead Publishing Limited, 2013

Millet 333

Table 9.8 Vitamin composition of proso millet and the recommended daily intake

Vitamins mg/100 g sample Recommended daily
(dry weight basis) intake (mg)a

Thiamine 0.56–0.66 0.2–1.4
1.82–6.39 2.0–18.0
Niacin 0.12–0.22 0.3–1.6
0.68–1.10 2.0–6.0
Riboflavin 0.1–1.5c
1.09
Pantothenic acid 78.93 –
Carotenoidsb 0.26 3.0–17.0
Cholined
Tocopherolse

aValues are those recommended by the German Nutrition Society (DGE) (2007) (http://

www.dge.de/modules.php?name=content&pa=showpage&pid=3&page=1) depending on age

groups, sex, and physiological condition.
bA part of the carotenoids (e.g. β-carotin) are precursors of vitamin A = provitamin A.
cValues in retinol-equivalent: 1 mg retinol-equivalent = 6 mg all-trans-β-carotene = 12 mg

other provitamin A carotenoids.
dCholine was formerly termed as vitamin B4.
eValues in α-tocopherol equivalent.

Sources: Gabrovská et al. (2002), Serna-Saldivar and Rooney (1995), Oelke et al. (1990),

Bookwalter et al. (1987).

millet is a good source of all B vitamins except for vitamin B12. The B vita-
mins are concentrated in the aleurone layer and germ. Removal of these
tissues by decortication reduces the amounts of B vitamins, whereas malting
and fermentation increase the amounts and their availability (Serna-
Saldivar and Rooney, 1995). Table 9.8 shows ranges of vitamin contents
measured in proso millet and the recommended daily intake.

9.4.4 Phenolic antioxidants
Antioxidants are widely believed to be important protectors against oxida-
tive damage, which has been implicated in a range of diseases including
cancer, cardiovascular disease, arthritis, and ageing (Kehrer, 1993). Pheno-
lics are good antioxidants because of their favourable redox potentials and
the relative stability of the aryloxy radical (Simic and Jovanovic, 1994).
Phenolic acids are hydroxylated derivatives of benzoic and cinnamic acids.
In proso millet (as well as sorghum and other millets), they are mainly
located in the outer layers but can also be found in the endosperm (Hahn
and Rooney, 1986; McDonough et al., 1986; Mattila et al., 2005).They possess
potential health-promoting properties, partly by virtue of their antioxida-
tive action (Mattila et al., 2005). Phenolic acids mostly appear in bound
forms with types of sugars or sterols.

Sterol esters and phenolic acids have a cholesterol-lowering effect and
are also effective antioxidants. Compounds of ferulic acids and sterols,
so-called sterylferulate esters, showed distinctive protective effects against

© Woodhead Publishing Limited, 2013

334 Cereal grains for the food and beverage industries

Table 9.9 Contents of total phenolic acids in proso
millet whole grain grits

Phenolic acids mg/kg sample
(dry weight basis)

Caffeic acid 1.2 ± 0.1
Ferulic acid 290.0 ± 8.8
Vanillic acid 12.3 ± 2.0
p-Coumaric acid 20.1 ± 1.4
p-Hydroxybenzoic acid
Syringic acid 3.4 ± 0.2
Ferulic acid dehydrodimers 2.3 ± 1.1
Total 87.2 ± 10.3
417.2

Source: Mattila et al. (2005).

LDL cholesterol (Katan et al., 2003). Rats fed with sorghum and proso
millet at 30 % (w/w) of the total diet demonstrated increased HDL choles-
terol level without changing total cholesterol level (Cho et al., 2000).
Hydroxycinnamic acids are more common than hydroxybenzoic acids and
consist of p-coumaric, caffeic, ferulic and sinapic acids. Several of these
phenolic acids are also found in grain products, with ferulic acid being the
most abundant (Shahidi and Naczk, 1995; Manach et al., 2004; Mattila et al.,
2005). Phenolic acids are particularly interesting as they are potentially
protective against cancer and heart diseases (Shahidi and Naczk, 1995;
Breinholt, 1999; Manach et al., 2004).

The amounts of phenolic acids in whole-grain millet grits were analysed
according to Mattila et al. (2005) (Table 9.9). The phenolic acids in proso
millet grits are mainly ferulic acid and p-coumaric acids, as well as ferulic
acid dehydrodimers. Shahidi and Chandrasekara (2010) found that among
several varieties of millet (kodo, finger, foxtail, proso, pearl and little millets),
proso millet possessed the least total phenolic content.

Although dietary tannins are often perceived to be detrimental,
Hagerman et al. (1998) suggest that tannins, or polymeric polyphenolics,
may be much more potent antioxidants than simple monomeric phenolics.
Although many small phenolics are pro-oxidants, tannins have little or no
pro-oxidant activity. However, the potential of tannins to diminish nutrient
digestibility must be balanced against their potential to serve as biological
antioxidants (Salunkhe et al., 1990). Lorenz (1983) determined the tannin
contents of 24 proso millet varieties with different seed colours according
to the modified vanillin-HCl (hydrochloric acid) method (Burns, 1971;
Maxson and Rooney, 1972). Dark-coloured seeds had higher tannin con-
tents than light-coloured seeds. As dehulling greatly reduced the levels of
tannin, it is obvious that they are mainly concentrated in the hulls. Amounts
of tannins detected in the millets ranged from 0.05 to 0.18 % catechin
equivalent at an average moisture level of 9.2 %. However, these values

© Woodhead Publishing Limited, 2013

Millet 335

should be regarded critically as the vanillin-HCL method is not specific in
that it extracts condensed tannins as well as monomeric flavanols and their
oligomers (Dykes and Rooney, 2006). Investigations on sorghums that do
not have a pigmented testa contain non-tannin phenolics that react with
the reagents and give some false positive ‘tannin values’ that are not really
tannins (Earp et al., 1981; Hahn and Rooney, 1986; Dykes et al., 2005).

Choi et al. (2007) determined the antioxidant activity of methanolic
extracts of white rice, black rice, red sorghum, brown rice, mungbean, foxtail
millet, proso millet, barley, and adlay, frequently consumed in Korea, and
correlated antioxidant activities with the antioxidant contents in the differ-
ent extracts. The concentrations of total polyphenolics and carotenoids in
the extracts were measured by spectrophotometric methods, and vitamin E
analysis was carried out using high-performance liquid chromatography
(HPLC). Proso millet showed significantly lower antioxidant activities and
contained lower polyphenolic contents than red sorghum and black rice but
similar amounts compared to white rice, brown rice, mungbean, foxtail
millet, barley and adlay. However, no correlation was found between anti-
oxidant activities and carotenoids and vitamin E derivatives. On the other
hand, Shahidi and Chandrasekara (2010) found higher antioxidative activ-
ity and reducing power in both bound and soluble phenolic extracts from
foxtail millet compared to proso millet.

9.5 Processing of proso millet

To make proso millet suitable for food production or as food ingredient, it
needs to be processed by one of a wide range of methods. Most change the
original chemical and physical composition of proso millet, as well as its
nutritional value in both positive and negative ways.

9.5.1 Decortication
Decortication by mortar and pestle or with abrasive dehullers removes the
grains’ outer layers; therefore, decorticated kernels have reduced levels of
crude fibre, ash and fat. The lysine content decreases to about 50 % whereas
the amounts of the other amino acids remain nearly the same (Serna-
Saldivar and Rooney, 1995).

9.5.2 Lipid-extraction from proso millet bran
Decortication removes the outer layer of the grains, e.g. the bran. Proso
millet bran is therefore a by-product of millet-based food manufacturing.
Defatted brans can be applied in whole-grain meals and low-calorie foods.
Devittori et al. (2000) compared two extraction methods – (i) supercritical
carbon dioxide-extraction (SC-CO2), and (ii) Soxhlet extraction using
petroleum ether for the extraction of lipids from proso millet bran. The

© Woodhead Publishing Limited, 2013

336 Cereal grains for the food and beverage industries

composition of crude oil extracted by SC-CO2 under optimal conditions
was similar to that of Soxhlet-extracted oil in terms of fatty acid profile and
levels of free fatty acids (FFA), unsaponifiables, peroxides and tocopherols.
The oils differed with respect to phospholipids (absent in SC-CO2-extracted
oil), metals and waxes (lower levels in SC-CO2-extracted oil).

9.5.3 Puffing of proso millet
Puffed grains are often used as breakfast cereals or as snack foods. During
puffing, grains are exposed to a very high pressure steam which causes the
grain to burst open (UMDA/FAO, 2007). Proso millet is capable of explo-
sive popping that is accompanied by a simultaneous large increase in
volume (Hoseney et al., 1983). The popping of millet results in a small,
porous, crunchy product with properties similar to those of popcorn. Thus,
an ideal food application of proso millet would be as a popped or puffed
whole-grain snack product (Delostlewis et al., 1992). Delostlewis et al.
(1992) examined the puffing quality of different varieties of proso millet
under varying moisture and pressure levels. The products puffed at mois-
ture levels of 15 or 18 % and 140 or 160 psi were more highly extended, less
dense and had a higher protein content, but had lower levels of ash and
total dietary fibre than those puffed at moisture levels of 12 % moisture
content and 120 psi.

9.5.4 Improving the storage stability of millet flour
Millets can be stored for a long period without substantial quality changes
if the kernels remain intact. However, quality rapidly deteriorates after
millet is ground into flour (Varrianomarston and Hoseney, 1983) as hydro-
lytic and oxidative changes occur in the lipids (Carnovale and Quaglia, 1973;
Lai and Varrianomarston, 1980). Poor storage quality has been attributed
largely to hydrolytic changes associated with the action of lipolytic enzymes
(Thiam, 1977). Ground millet storage stability is improved by dry-milling
processes, which remove the major lipid-containing portions of the grain
(germ, covering layers) from the endosperm.

Another method to improve storage stability of proso millet was pre-
sented by Bookwalter et al. (1987). They adjusted whole millets to 15 %
moisture and gradually heated them up to 97 °C over 12 min by passing
them through a steam-jacketed paddle-conveyer to inactivate lipid enzymes.
The millets were then milled to 50 % and 80 % extraction flour. The 80 %
flour contained germ fractions, which resulted in much higher protein, lipid,
thiamine, riboflavine, niacin, iron, zinc, available lysine and protein effi-
ciency ratios than the 50 % flour. After storage at 49 °C, peroxide and fat
acidity values were lower and flavour scores higher for processed than for
unprocessed millet flours. No differences between processed and unpro-
cessed flours were found in terms of birefringence, water absorption and

© Woodhead Publishing Limited, 2013

Millet 337

solubility, visco-amylograph values, or in their use in several foods. The
retention of stabilizing germ fractions in the final milled product improved
both nutritional quality and yield.

9.5.5 Milling characteristics
Coarse proso millet flours have a higher ash content than fine flours; thus,
with reference to milling, an increased grain moisture content leads to a
higher percentage of ash since the proportion of coarse flour produced is
increased. In contrast to this, the milling yield (percentage extraction)
decreases due to the higher ash content. The level of extraction of fine flour
may decrease as more total water becomes available, thus making the endo-
sperm softer and finer and tending to obstruct the sieves of the milling
device. Increasing the temper time led to decreased ash percentages as well
as decreased extraction yields. However, ash percentage approached con-
stant levels after 2 h tempering at levels of moisture greater than 15 %.
Higher temper moistures were maintained to decrease particle size of both
the coarse and fine flours, whereas at higher temper times only the size of
the fine flour particles was affected (Lorenz and Dilsaver, 1980; Yanez and
Walker, 1986).

9.5.6 Malting
Malting is a very important step in the production of basic raw materials
for eventual food production. The malting conditions are very dependent
on the grain itself, e.g. on the respective variety and the growing conditions.
Khan et al. (1997) ascertained that differences in water uptake and inci-
dence of imbibitions damage in proso millet biotypes were associated with
seed coat colour. Varieties that had entirely or partly light-coloured seed
coats imbibed rapidly and suffered major imbibitions damage. The major
factor influencing water uptake was most probably the permeability of the
seed coat. Coloured seed coats are heavier and therefore presumably
thicker than those of light-coloured seeds. The permeability of dark-
coloured seed coats may be reduced by the physical barrier of greater cell
numbers, differences in cell density or by some chemical reaction (phenolic
oxidation) unique to coloured seeds. Rates of germination were related to
the rate of water uptake. Dark-pigmented seeds showed a slower rate of
seed germination than light-coloured seeds. White-pigmented seeds took
the shortest time to achieve maximum germination (36 h), while one black-
pigmented seed took the longest (108 h).

Parameswaran and Sadasivam (1994) made an attempt to study the
effect of germination on the protein and carbohydrate profile of proso
millet grains. They soaked the grains overnight in distilled water at room
temperature and spread them out evenly on filter paper, which was moist-
ened at regular intervals of 24 h. The germination was carried out at room

© Woodhead Publishing Limited, 2013

338 Cereal grains for the food and beverage industries

temperature for one to eight days in the dark. During germination, the
protein content did not differ much in the earlier days, but then increased
gradually. This was due to the loss of dry matter percentage during germina-
tion. After the first day of germination, changes in the relative amount of
the protein fractions were observed. The albumin and globulin fraction
continued to increase and the prolamin fraction continued to decrease
(Parameswaran and Sadasivam, 1994). Little difference was noticed in the
glutelin fraction.As germination proceeded, the extractability of the protein
was found to increase. The changes in the contents of non-polar nitrogen,
free amino acids, lysine, tryptophan and methionine during germination
increased and reached a maximum on the sixth day of germination after
which they declined. The most striking changes in the amino acids upon
germination were the large increases in lysine and tryptophan contents. It
is presumed that the significant increases in lysine during germination can
be attributed to de novo synthesis.

With reference to changes in the carbohydrate profile, Parvathy and
Sadasivam (1982) observed a decrease in the starch content and an appar-
ent initial increase in the amylose content. These changes might be caused
by limited α-amylolysis of both components of starch by α-amylase. During
germination, the amount of sugars increased drastically, which can be attrib-
uted to the degradation of starch (Fig. 9.5). The decrease in the starch
content was not totally reflected in the total carbohydrate content which
may be due to the partial compensation by simple sugars derived from
starch (Briggs et al., 1981).

Zarnkow et al. (2007) investigated the influence of the different malting
parameters – e.g. germination time, degree of steeping and temperature on
the quality of proso millet malt.They concluded that proso millet has poten-
tial as a raw material for malting purposes using commonly-employed
malting procedures and equipment. Furthermore, they pointed out its
gluten-free status, which makes it suitable for the production of beverages
designed for coeliac patients.The optimal quality parameters with reference
to the use of this malt for brewing (extract, apparent attenuation limit,
α-amylase activity and β-amylase activity) were achieved after five days’
germination time, 44 % moisture content and a constant temperature of
22 °C during steeping and germination. The values obtained for the amylo-
lytic and cytolytic attributes were 64.8 % extract, 1.383 mPa·s viscosity, 76 %
apparent attenuation limit, 111 U/g α-amylase activity and 102 U/g
β-amylase activity. However, when investigating the influence of different
varieties of proso millet, a wide range within the amylolytic, proteolytic
and cytolytic attributes could be observed (Zarnkow et al., 2010b). These
authors conclude that the majority of the varieties evaluated were unsuit-
able for brewing process. The variety showing properties closest to those of
barley was ‘Braune Wildform’. In addition to the good performance of this
variety in malting trials, an added advantage is its widespread availability
in Europe.

© Woodhead Publishing Limited, 2013

Millet 339

(1)

5 kV ×5,000 5 μm 0000 Test 1 5 kV ×5,000 5 μm 0000 Test 1
(a) (b)

(2)

5 kV ×5,000 5 μm 0000 Test 1 5 kV ×5,000 5 μm 0000 Test 1
(c) (d)

Fig. 9.5 Scanning electron microscope (SEM) micrograph of starch of the floury
(1) and vitreous (2) endosperm unmalted (a, c) and after 77 h of malting (b, d).
Reprinted from Zarnkow et al., 2007, with permission from the Journal of the Ins-

titute of Brewing.

9.6 Food and beverage applications of proso millet

Millets have long been utilized to make traditional staple foods by a large
proportion of the world’s poor, especially in Asia and Africa. Currently,
millets are consumed in northern China, India, Africa and southern Russia,
with about 80 % of the world’s millet production directly consumed as
human food, such as thick or thin porridges, steamed food products, cakes,
fermented and unfermented breads, snacks, weaning foods and alcoholic
and non-alcoholic beverages, etc.

9.6.1 Baking
Bread
As proso millet does not have gluten-forming proteins, leavened breads
cannot be made with 100 % millet flours. Using 100 % millet flour produces
rather compact breads with a dense texture. Therefore, the breads produced

© Woodhead Publishing Limited, 2013

340 Cereal grains for the food and beverage industries

are usually flat breads, particularly in Eastern Europe and Africa (Schery,
1963). Lorenz and Dilsaver (1980) analysed the influence of the blend com-
position of wheat flour and proso millet flour on baking properties and the
quality of bread. The grains of the breads were satisfactory up to a 15 %
substitution level. Crumb colour became darker with increasing amounts
of millet in the formulation. The nutty taste of the bread baked with millet
flour was very pleasant. At the 20 % level, a slightly objectionable grittiness
was detected, mainly due to the high ash content.

Recently, Singh et al. (2012) optimized a bread prepared from millet-
based composite flours. In more detail, two types of composite flours were
made by blending wheat, barnyard-millet flour and gluten (BWCF) and
wheat, finger-millet, proso-millet and barnyard-millet flours (BFPWCF).
BWCF bread was formulated using 61.8 g/100 g barnyard-millet, 31.4 g/
100 g wheat and 6.8 g/100 g gluten, while BFPWCF was developed using
9.1 g/100 g barnyard, 10.1 g/100 g finger-millet, 10.2 g/100 g proso-millet
and 69.6 g/100 g wheat. The sensory study showed that the acceptability of
bread samples prepared from composite flours (BWCF and BFPWCF) was
almost equal to the wheat bread (WB) which was used as reference, dem-
onstrating (proso) millet functionality for bread-making purposes.

Cookies
Lorenz and Dilsaver (1980) examined the impact of proso millet flour on
the quality of cookies by blending the millet flour and cookie flour in four
different formulations. Cookie spread factors increased and top grain scores
improved with increasing amounts of proso millet flours, presumably due
to the high fat content of proso millet flours (Lorenz and Dilsaver, 1980).
Cookies with increasing amount of proso millet became darker in colour
and were rated as very satisfactory by the sensory panel.

Noodles
Lorenz and Dilsaver (1980) also prepared and evaluated noodles made
from a blend of proso millet flour and wheat flour. Sensory evaluation
indicated that noodles with up to 20 % proso millet flour are quite accept-
able. Moreover, the cooking losses for the control noodles and for those
prepared with 20 % millet flour were approximately the same. However, the
maximum possible replacement level appeared to be 60 % since higher
levels induced difficulties with extruding the noodles using a pasta press.

Traditional proso millet foods and beverages
There are a wide variety of traditional millet-based foods and beverages in
countries in the African continent, the Indian sub-continent and the Far
East (China). The preparations differ widely depending on local recipes.
Detailed classifications of traditional foods from sorghum and millets have
been developed over the last few decades (Vogel and Graham, 1979; Rooney
et al., 1986).They can commonly be classified into breads, porridges, steamed

© Woodhead Publishing Limited, 2013

Millet 341

products, boiled products, beverages and snack foods (Rooney et al., 1986;
Rooney and McDonough, 1987). However, the number of traditional
recipes for proso millet in the literature is very low as most of the recipes
are based on other sorts of millets e.g. pearl millet (P. glaucum) or finger
millet (Eleusine coracana). Lin et al. (1998) named two traditional recipes
from the Shanxi Province in China that use proso millets as basic ingredi-
ents. Proso millet oil pudding is a kind of a fried dumpling filled with cooked
red beans, described as pale on the outer surface with a delicate texture
inside and a sweet aroma. Sour meal is a kind of soup, which is made of
sweet sour fermented soybean flour (sour soup) in which proso millet is
soaked overnight. The taste is characterized as moderately sweet and sour.
A high digestibility was recorded and it is recommended in cases of sun-
stroke (Corke et al., 1998).

9.6.2 Brewing
Bosa, also called busa or bouza (Arici and Daglioglu, 2002), a product from
the Balkans, Egypt, Sudan and Turkey, is one of the beers traditionally
produced from proso millet. It is a bread-beer and its methods of manufac-
ture are said to resemble those used by ancient Egyptian brewers (Lucas,
1962; Darby et al., 1977). The name is derived from buze, the Persian word
for millet. Boza can be brewed from various cereals, but proso millet is
preferred. It is a thick liquid, with a pale yellow colour and a characteristic
acid–alcoholic aroma. The alcohol content is generally less than 1 % vol,
whereas, in contrast, boza from Egypt can contain up to 7 %. To produce
this beer, about three-quarters of the proso millet is coarsely ground and
kneaded with water. Alternatively, the dough is made with a mixture of
malted and unmalted millets, with yeast added as sourdough.After a period,
the dough is formed into loaves, which are baked slightly. Presumably some
of the yeast and millet enzymes survive. The remaining millet is wetted and
is exposed to the air to let it malt; alternatively, limited germination in the
soil may be used. The matted roots are removed by hand, after the malt
has been dried, rubbed to break them up, and sifted to separate the frag-
ments. The green malt may be used directly, or after it has been dried by
the sun. It is crushed and mixed with broken lumps of the bread and water.
The mixture begins to ferment, sometimes after some old boza has been
added to provide an inoculum of microbes. After a period the mixture is
roughly filtered to remove the coarse solids (Briggs, 1998).

In addition, Zarnkow et al. (2010b) established a mashing procedure to
produce good-quality wort as a basis for gluten-free beer. They concluded
that a usual infusion mashing procedure applied for barley malt cannot be
used for proso millet malt. This is due to the fact that the gelatinization
temperature of proso millet malt is relatively high compared to the gelati-
nization temperature of barley malt. Furthermore, enzymatic activities
are relatively low and their maximum levels are reached below the

© Woodhead Publishing Limited, 2013

342 Cereal grains for the food and beverage industries

gelatinization temperature. They detected optimum temperatures and pH
values of 60 °C and pH 5.0 for α-amylase, 40 °C and pH 5.3 for β-amylase
and 50 °C and pH 5.3 for limit-dextrinase. Therefore, they suggested a modi-
fied decoction mashing regime in which 40 % of the total mash was heated
to 68 °C (to ensure starch gelatinization) and mixed together after 10 min
with the remaining mash (at 22 °C) in order to achieve 40 °C. At this point,
the pH was adjusted to 5.3 using lactic acid. After a resting period of 20 min,
the mash was heated to 50 °C and this temperature was held for another
20 min. The temperature of the mash was then increased to 60 °C and the
pH was adjusted to 5.0. After 30 min, the mash was heated to 70 °C (mash-
off temperature) to diminish wort viscosity, thereby improving lauter
performance. Lautering was performed in a lauter tun. The wort quality
achieved with this mashing regime was within the range of published data
for worts produced from barley malt. A major advantage of wort from
proso millet malt was its high zinc content (1.8 mg/L compared to 0.01–
1.08 mg/L found in barley malt worts). On the other hand, it also a relative
high thiobarbituric acid index (TBI) which could be regarded as critical, as
high TBI values usually correlate with negative influence on flavour stabil-
ity in the final beer.

Zarnkow et al. (2010a) additionally investigated the impact of two tem-
peratures and the use of five different yeast strains (species) in fermentation
on the quality of beer produced from malted proso millet. They observed
strong similarities in the fermentation performance of various Saccharo-
myces strains and almost no temperature dependence, whereas the use of
Brettanomyces strains led to significantly higher fermentation rates and
a more significant impact of temperature on the process. However, they
concluded that, in general, the beers brewed using proso millet malt and
fermented with the selected yeast strains possessed a range of aroma
compounds which are comparable to those found in beer produced from
barley malt.

9.7 Future trends

Climatic change is expected to confront us with three challenges: (i) an
increase in temperatures of up to 2–5 °C; (ii) increasing water stress; and
(iii) severe malnutrition. In the future, millets are likely to become far more
important food grains globally given their ability to grow under hot and dry
conditions and because they are adapted to a wide range of ecological
conditions (they often grow on low-fertility soils, do not demand chemical
fertilizer and are usually not affected by pests). In the developing world,
the need for food security surely increases the demand for millet to become
a commercially traded grain and one that is processed into food products,
instead of just a subsistence crop. As none of the millets are closely related
to wheat, they are appropriate foods for those with coeliac disease or other

© Woodhead Publishing Limited, 2013

Millet 343

forms of allergy or intolerance to wheat. Moreover, millets represent an
optimal ingredient in gluten-free formulations because they are rich in B
vitamins and minerals known to be deficient in gluten-free products
(Hopman et al., 2006). However, millets are also a mild thyroid peroxidase
inhibitor (C-glycosylflavone) and probably should not be consumed in great
quantities by those with thyroid disease (goiter) (Gaitan et al., 1989). Further
research is required to resolve several scientific and technological problems
associated with millet. Two examples are as follows: a more efficient way of
milling the grain to reduce losses needs to be found, and whether or not
millet is a significant goitrogen needs to be determined.

9.8 References

aacc (2001). The definition of dietary fiber. Cereal Foods World, 46, 112–126.
anderson, p. a. (1985). Interactions between proteins and constituents that affect

protein quality. In: finley, j. w. and hopkins, d. t. (eds) Digestibility and Amino
Acid Availability in Cereals and Oilseeds. St Paul, MN: AACC, International, Inc.
arici, m. and daglioglu, o. (2002). Boza: A lactic acid fermented cereal beverage as
a traditional Turkish food. Food Reviews International, 18, 39–48.
asp, n. g., johansson, c. g., hallmer, h. and siljestrom, m. (1983). Rapid enzymatic
assay of insoluble and soluble dietary fiber. Journal of Agricultural and Food
Chemistry, 31, 476–482.
baltensperger, d. d. (1996). Foxtail and proso millet. In: janick, j. (ed.) Progress in
New Crop. Alexandria, VA: ASHS Press.
baltensperger, d. d. (2002). Progress with proso, pearl and other millets. In: janick,
j. and whipkey, a. (ed.) Trends in New Crops and New Uses. Alexandria, VA:
ASHS Press.
becker, r. and lorenz, k. (1978). Saccharides in proso and foxtail millets. Journal of
Food Science, 43, 1412–1414.
becker, r., lorenz, k. and saunders, r. m. (1977). Saccharides of maturing triticale,
wheat, and rye. Journal of Agricultural and Food Chemistry, 25, 1115–1118.
belitz, h.-d., grosch w. and schieberle, p. (2009). Food Chemistry. Berlin; Heidel-
berg: Springer.
bewley, j. d. and black, m. (1985). Seeds: Physiology of Development and Germina-
tion. New York: Plenum Press.
bookwalter, g. n., lyle, s. a. and warner, k. (1987). Millet processing for improved
stability and nutritional quality without functionality changes. Journal of Food
Science, 52, 399–402.
breinholt, v. (1999). Desirable versus harmful levels of intake of flavonoids and
phenolic acids. In: kumpulainen, j. and salonen, j. (eds) Natural Antioxidants and
Anticarcinogens in Nutrition, Health, and Disease. Cambridge: The Royal Society
of Chemistry.
briggs, d. e. (1998). Malts and Malting. London; New York: Blackie Academic.
briggs, d. e., hough, j. s., stevens r. and young, j. w. (1981). Malting and Brewing
Science. New York: Chapman and Hall.
brites, c., cruz t. r., santos c. a., guerra m., vargues a. and beirão dacosta, m. l.
(2004). Physico-chemical characterization of varieties of rice of different
cooking and eating qualities. In: ferrero, a. and vidotto, f. (eds) Challenges and
opportunities for Sustainable Rice-Based Production Systems. Torino: Edizione
Mercuri.

© Woodhead Publishing Limited, 2013

344 Cereal grains for the food and beverage industries

burgener, p. a., feuz, d. m. and holman, t. (2002). Historical crop prices, seasonal
patterns and futures basics for the Nebraska panhandle 1983–2001. Lincoln, NE:
University of Nebraska, Cooperative Extension Institute.

burns, r. e. (1971). Method for estimation of tannin in grain sorghum. Agronomy
Journal, 63, 511–512.

carnovale, e. and quaglia, g. b. (1973). Influence of temperature and humidity
controlled preservation on the chemical composition of milling products from
millet. Annals de Technologic Agricole, 22, 371–380.

casey, p. and lorenz, k. (1977). Millet – functional and nutritional properties. Bakers
Digest, 51, 45–57.

chandrasekher, g., raju, d. s. and pattabiraman, t. n. (1982). Natural plant enzyme-
inhibitors – protease inhibitors in millets. Journal of the Science of Food and
Agriculture, 33, 447–450.

chiba, s., kanaya, k., hiromi, k. and shimomura, t. (1979). Substrate-specificity and
subsite affinities of buckwheat alpha-glucosidase. Agricultural and Biological
Chemistry, 43, 237–242.

cho, s. h., choi, y. and ha, t. y. (2000). In vitro and in vivo effects of prosomillet,
buckwheat and sorghum on cholesterol metabolism. Faseb Journal, 14,
A249–A249.

choi, y., jeong, h.-s. and lee, j. (2007). Antioxidant activity of methanolic extracts
from some grains consumed in Korea. Food Chemistry, 103, 130–138.

corke, h., lin, r. and li, w. (1998). Spotlight on Shanxi Province, China – its minor
crops and specialty foods. Cereal Foods World, 43, 189–192.

cronin, f. j. and shaw, a. m. (1988). Summary of dietary recommendations for
healthy Americans. Nutrition Today, 6, 26–33.

darby, w. j., ghalioungui, p. and grivetti, l. (1977). Food:The Gift of Osiris. London:
Academic Press.

delostlewis, k., lorenz, k. and tribelhorn, r. (1992). Puffing quality of experimen-
tal varieties of proso millets (Panicum Miliaceum). Cereal Chemistry, 69,
359–365.

devittori, c., gumy, d., kusy, a., colarow, l., bertoli, c. and lambelet, p. (2000).
Supercritical fluid extraction of oil from millet bran. Journal of the American Oil
Chemists Society, 77, 573–579.

dykes, l. and rooney, l. w. (2006). Sorghum and millet phenols and antioxidants.
Journal of Cereal Science, 44, 236–251.

dykes, l., rooney, l. w., waniska, r. d. and rooney, w. l. (2005). Phenolic com-
pounds and antioxidant activity of sorghum grains of varying genotypes. Journal
of Agricultural and Food Chemistry, 53, 6813–6818.

eksittikul, t., svendsby, o., yamaguchi, h., iizuka, m. and minamiura, n. (1993). Thai
rice seed alpha-glucosidase and its specificity. Bioscience Biotechnology and Bio-
chemistry, 57, 319–321.

englyst, h. n., kingman, s. m. and cummings, j. h. (1992). Classification and measure-
ment of nutritionally important starch fractions. European Journal of Clinical
Nutrition, 46, S33–S50.

european union (2010). Eurostat database. Available at: http://epp.eurostat.ec.
europa.eu/portal/page/portal/eurostat/home [accessed November 2012].

earp, c. f., akingbala, j. o., ring, s. h. and rooney, l. w. (1981). Evaluation of
several methods to determine tannins in sorghums with varying kernel charac-
teristics. Cereal Chemistry, 58, 234–238.

fao/ who/unu (1985). Energy and protein requirements; report of a joint FAO/ WHO/
UNU expert consultation. WHO Technical Report Series 724. Geneva: WHO.

fao/un (2012). FAOSTAT database: http://faostat3.fao.org/home/index.html.

ferriola, d. and stone, m. (1998). Sweetener effects on flaked millet breakfast
cereals. Journal of Food Science, 63, 726–729.

© Woodhead Publishing Limited, 2013

Millet 345

fuwa, h., tomita, y., sugimoto, y. and sakamoto, s. (1981). Some properties of
starches of grain amaranths and several millets. Journal of Nutritional Science and
Vitaminology, 27, 471–484.

gabrovska, d., fiedlerova, v., holasova, m., maskova, e., smrcinov, h., rysova, j.,
winterova, r., michalova, a. and hutar, m. (2002). The nutritional evaluation
of underutilized cereals and buckwheat. Food and Nutrition Bulletin, 23, 246–
249.

gaitan, e., lindsay, r. h., reichert, r. d., ingbar, s. h., cooksey, r. c., legan, j.,
meydrech, e. f., hill, j. and kubota, k. (1989). Antithyroid and goitrogenic effects
of millet: role of C-glycosylflavones. Journal of Clinical Endocrinology & Metabo-
lism, 68, 707–714.

gallant, d. j., bouchet, b. and baldwin, p. m. (1997). Microscopy of starch: evidence
of a new level of granule organization. Carbohydrate Polymers, 32, 177–191.

geervani, p. and eggum, b. o. (1989). Nutrient composition and protein-quality of
minor millets. Plant Foods for Human Nutrition (formerly Qualitas Plantarum),
39, 201–208.

gopalan, c., rama sastri, a. and balasubramanian, s. c. (1980). Nutritive Value of
Indian Foods. Hyderabad: National Institute of Nutrition.

hagerman, a. e., riedl, k. m., jones, g. a., sovik, k. n., ritchard, n. t., hartzfeld,
p. w. and riechel, t. l. (1998). High molecular weight plant polyphenolics (tannins)
as biological antioxidants. Journal of Agricultural and Food Chemistry, 46,
1887–1892.

hahn, d. h. and rooney, l. w. (1986). Effect of genotype on tannins and phenols of
sorghum. Cereal Chemistry, 63, 4–8.

hanelt, p. (1981). Zur Geschichte des Anbaus von Buchweizen und Rispenhirse in
der Lausitz. Abh. Ber [About history of cultivation of buckwheat and millet in
Lusatia]. Papers and Reports Museum of Natural History, Görlitz, 55, 1–13.

henson, c. a. and sun, z. (1995). Barley seed alpha-glucosidases:Their characteristics
and roles in starch degradation. Enzymatic Degradation of Insoluble Carbohy-
drates, 618, 51–58.

hinze, g. (1972). Millets in Colorado, Bulletin 553S. Fort Collins, CO: Colorado State
University Experiment Station.

hoffmann-bahnsen, r. and plessow, j. (2003). Alte Kulturpflanzen neu entdeckt,
Rispenhirse (Panicum miliaceum) eine ideale Sommerung für den ökologischen
Landbau [Ancient crops newly discovered, Millet (Panicum miliaceum) an ideal
summer crop for organic farming. Mitteilungen der gesellschaft fur Pflanzenbau-
wissenschaften, 15, 31–33.

hopman, e. g., le cessie, s., von blomberg, b. m. and mearin, m. l. (2006). Nutritional
management of the gluten-free diet in young people with celiac disease in The
Netherlands. Journal of Pediatric Gastroenterology and Nutrition, 43, 102–108.

hoseney, r. c., zeleznak, k. and abdelrahman, a. (1983). Mechanism of popcorn
popping. Journal of Cereal Science, 1, 43–52.

hsu, h. w., vavak, d. l., satterlee, l. d. and miller, g. a. (1977). Multienzyme tech-
nique for estimating protein digestibility. Journal of Food Science, 42, 1269–
1273.

hulse, j. h., laing, e. m. and pearson, o. e. (1980). Sorghum and the Millets: Their
Composition and Nutritional Value. New York: Academic Press.

humphrys, c. (2005). Raps und hirse im biologischen anbau [Rape and millet in
organic farming]. Biolandbau [Organic Farming] Congress, 25 November, LBBZ
Arenenberg.

hurrell, r. f. (2003). Influence of vegetable protein sources on trace element and
mineral bioavailability. Journal of Nutrition, 133, 2973s–2977s.

iupac (1994). Carbohydrates. In: Glossary of class names of organic compounds
and reactive intermediates based on structure (IUPAC recommendations 1994).

© Woodhead Publishing Limited, 2013

346 Cereal grains for the food and beverage industries

Research Triangle Park, NC: IUPAC. Available at: http://www.chem.qmul.ac.uk/
iupac/class/carbo.html#08 [accessed December 2012].
jones, r. w., beckwith, a. c., khoo, u. and inglett, g. e. (1970). Protein composition
of proso millet. Journal of Agricultural and Food Chemistry, 18, 37–39.
kakade, m. l., simons, n. and liener, i. e. (1969).An evaluation of natural vs synthetic
substrates for measuring antitryptic activity of soybean samples. Cereal Chemistry,
46, 518–526.
kakade, m. l., swenson, d. h. and liener, i. e. (1970). Note on determination of
chymotrypsin and chymotrypsin inhibitor activity using casein. Analytical Bio-
chemistry, 33, 255–258.
kalinova, j. and moudry, j. (2006). Content and quality of protein in proso millet
(Panicum miliaceum L.) varieties. Plant Foods for Human Nutrition (formerly
Qualitas Plantarum), 61, 45–49.
kasaoka, s., oh-hashi, a., morita, t. and kiriyama, s. (1999). Nutritional characteriza-
tion of millet protein concentrates produced by a heat-stable α-amylase digestion.
Nutrition Research, 19(6), 899–910.
katan, m. b., grundy, s. m., jones, p., law, m., miettinen, t., paoletti, r. and
participants, s. w. (2003). Efficacy and safety of plant stanols and sterols in
the management of blood cholesterol levels. Mayo Clinic Proceedings, 78,
965–978.
kehrer, j. p. (1993). Free radicals as mediators of tissue injury and disease. Critical
Reviews in Toxicology, 23, 21–48.
kemper center for home gardening (2005). Panicum miliaceum. Available at:
http://www.mobot.org/gardeninghelp/plantfinder/Plant.asp?code=A758 [accessed
November 2012].
khan, m., cavers, p. b., kane, m. and thompson, k. (1997). Role of the pigmented seed
coat of prose millet (Panicum miliaceum L) in imbibition, germination and seed
persistence. Seed Science Research, 7, 21–25.
knörzer, k. h., gerlach, r., meurers-balke, j., kalis, a. j., tegtemaier, u., becker,
w. d. and jurgens, a. (1999). Pflanzenspuren, Archäobotanik im Rheinland:
Agrarlandschaft und Nutzpflanzen im Wandel der Zeiten [Plant traces, Archaebo-
tanic in Rhine: Agricultural landscape and crop in change of time], Cologne,
Rhineland.
kohama, k., nagasawa, t. and nishizawa, n. (1999). Polypeptide compositions and
NH2-terminal amino acid sequences of proteins in foxtail and prose millets. Bio-
science Biotechnology and Biochemistry, 63, 1921–1926.
kolb, r. t. (1992). Landwirtschaft im Alten China [Agriculture in ancient China].
Berlin: Systemata Mundi.
kumari, s. k. and thayumanavan, b. (1997). Comparative study of resistant starch
from minor millets on intestinal responses, blood glucose, serum cholesterol and
triglycerides in rats. Journal of the Science of Food and Agriculture, 75, 296–302.
kumari, s. k. and thayumanavan, b. (1998). Characterization of starches of proso,
foxtail, barnyard, kodo, and little millets. Plant Foods for Human Nutrition (for-
merly Qualitas Plantarum), 53, 47–56.
kutty, a. v. m. and pattabiraman, t. n. (1986). Specificity of plant amylase inhibitors
on 10 pancreatic alpha-amylases. Journal of Food Biochemistry, 10, 117–124.
lai, c. c. and varrianomarston, e. (1980). Changes in pearl-millet meal during
storage. Cereal Chemistry, 57, 275–277.
leach, h. w., mccowen, l. d. and schoch, t. j. (1959). Structure of the starch granule.
1. swelling and solubility patterns of various starches. Cereal Chemistry, 36,
534–544.
léder, i. (2004). Sorghum and millets. In: füleky, g. (ed.) Cultivated Plants, Primarily
as Food Sources: Encyclopedia of Life Support Systems (EOLSS), Developed
under the Auspices of the UNESCO. Oxford: EOLSS.

© Woodhead Publishing Limited, 2013

Millet 347

liener, i. e. and kakade, m. l. (1980). Protease inhibitors. In: liene, e. (ed.) Toxic
Constituents of Plant Foodstuffs. New York: Academic Press.

lin, r., li, w. and corke, h. (1998). Spotlight on Shanxi Province China: Its minor
crops and specialty foods. Cereal Foods World, 43(4), 189–192.

lorenz, k. (1977). Proso and foxtail millets – scanning electron-microscopy
and starch characteristics. Lebensmittel Wissenschaft and Technologie, 10, 324–
327.

lorenz, k. (1983). Tannins and phytate content in proso millets (Panicum milia-
ceum). Cereal Chemistry, 60, 424–426.

lorenz, k. and dilsaver, w. (1980). Rheological properties and food applications of
proso millet flours. Cereal Chemistry, 57, 21–24.

lorenz, k. and hinze, g. (1976). Functional characteristics of starches from
proso and foxtail millets. Journal of Agricultural and Food Chemistry, 24,
911–914.

lorenz, k. and hwang, y. s. (1986). Lipids in proso millet (Panicum miliaceum) flours
and brans. Cereal Chemistry, 63, 387–390.

lorenz, k. and saunders, r. m. (1978). Enzyme activities in commercially milled rice.
Cereal Chemistry, 55, 77–86.

lucas, a. (1962). Ancient Egyptian Materials and Industries. London: Edward
Arnold.

lysov, v. n. (1968). Proso. Leningrad: Kolos.
manach, c., scalbert, a., morand, c., remesy, c. and jimenez, l. (2004). Polyphenols:

food sources and bioavailability. American Journal of Clinical Nutrition, 79,
727–747.
marathee, j. p. (1994). Structure and characteristics of the world millet economy. In:
riley, k. w., gupta, s. c., seetharam, a. and mushonga, j. n. (eds) Advances in
Small Millets. New York: International Science.
matsui, h., chiba, s. and shimomura, t. (1978). Substrate-specificity of an alpha-
glucosidase in sugar-beet seed. Agricultural and Biological Chemistry, 42, 1855–
1860.
mattila, p., pihlava, j. m. and hellstrom, j. (2005). Contents of phenolic acids, alkyl-
and alkenylresorcinols, and avenanthramides in commercial grain products.
Journal of Agricultural and Food Chemistry, 53, 8290–8295.
matz, s. a. (1986). Millet, wild rice, adlay, and rice grass. Cereal Science. Westport,
CT: AVI Press.
matzke, h. j. (1998). Impact of processing on bioavailability examples of minerals
in foods. Trends in Food Science & Technology, 9, 320–327.
maxson, e. d. and rooney, l. w. (1972). Two methods of tannin analysis for Sorghum
bicolor (L.) Moench grain. Crop Science, 12, 252–253.
mazurs, e. g., schoch, t. j. and kite, f. e. (1957). Graphical analysis of the Brabender
viscosity curves of various starches. Cereal Chemistry, 34, 141–152.
mcdonough, c. m., rooney, l. w. and earp, c. f. (1986). Structural characteristics of
eleusine corocana (finger millet) using scanning electron and fluorescence micro-
scopy. Food Microstructure, 5, 247–256.
nagaraj, r. h. and pattabiraman, t. n. (1985). Purification and properties of an alpha-
amylase inhibitor specific for human pancreatic amylase from proso (Panicium
Miliaceum) seeds. Journal of Biosciences, 7, 257–268.
nishizawa, n., oikawa, m., nakamura, m. and hareyama, s. (1989). Effect of lysine
and threonine supplement on biological value of proso millet protein. Nutrition
Reports International, 40, 239–245.
nishizawa, n., sato, d., ito, y., nagasawa, t., hatakeyama, y., choi, m. r., choi, y. y.
and wei, y. m. (2002). Effects of dietary protein of proso millet on liver injury
induced by D-galactosamine in rats. Bioscience Biotechnology and Biochemistry,
66, 92–96.

© Woodhead Publishing Limited, 2013

348 Cereal grains for the food and beverage industries

nomura, t., kono, y. and akazawa, t. (1969). Enzymic mechanism of starch break-
down in germinating rice seeds .2. Scutellum as site of sucrose synthesis. Plant
Physiology, 44, 765–769.

oelke, e. a., oplinger, e. s., putnam, d. h., durgan, b. r., doll, j. d. and undersander,
d. j. (1990). Millets. Alternative Field Crops Manual. Available at: http://
www.hort.purdue.edu/newcrop/afcm/millet.html [accessed December 2012].

oelz, o. (1982). The clinical significance of prostaglandins and other arachidonic
metabolites. Therapeutische Umschau, 39, 751–758.

osborne, t. b. (1907). The Proteins of the Wheat Kernel. Washington DC: Carnegie
Institute of Washington.

parameswaran, k. p. and sadasivam, s. (1994). Changes in the carbohydrates and
nitrogenous components during germination of proso millet, Panicum Miliaceum.
Plant Foods for Human Nutrition (formerly Qualitas Plantarum), 45, 97–102.

parameswaran, k. p. and thayumanavan, b. (1995). Homologies between prolamins
of different minor millets. Plant Foods for Human Nutrition (formerly Qualitas
Plantarum), 48, 119–126.

parvathy, k. and sadasivam, s. (1982). Comparison of amylase activity and carbo-
hydrate profile in germinating seeds of Setaria Italica, Echinochloa Frumentacea,
and Panicum Miliaceum. Cereal Chemistry, 59, 543–544.

ravindran, g. (1991). Studies on millets: Proximate composition, mineral composi-
tion, and phytate and oxalate contents. Food Chemistry, 39, 99–107.

ravindran, g. (1992). Seed protein of millets – amino acid composition, proteinase-
inhibitors and in vitro protein digestibility. Food Chemistry, 44, 13–17.

resurreccion, a. p., juliano, b. o. and tanaka, y. (1979). Nutrient content and dis-
tribution in milling fractions of rice grain. Journal of the Science of Food and
Agriculture, 30, 475–481.

ring, s. g. and parker, r. (2001). Aspects of the physical chemistry of starch. Journal
of Cereal Science, 34, 1–17.

rooney, l. w. and mcdonough, c. m. (1986). Food quality and consumer acceptance
of pearl millet. In: witcombe, j. r. and beckerman, s. r. (eds) Pearl Millet: Inter-
national Workshop Proceedings. Patancheru: ICRISAT, 43–61.

rooney, l. w., kirleis, a. w. and murty, d. s. (1986). Traditional foods from sorghum:
their production evaluation and nutritional value. In: pomeranz, y. (ed.) Advances
in Cereal Science and Technology, Vol. 8. St Paul, MN: AACC International, Inc.,
317–353.

salgo, a., ganzler, k. and jescai, t. (1985). Simple enzymatic methods for prediction
of plant protein digestibility. In: lasztity, r. r. and hidevegi, m. (eds) Amino Acid
Composition and Biological Value of Cereal Proteins. Budapest: Springer.

salunkhe, d. k., chavan, j. k. and kadam, s. s. (1990). Dietary Tannins: Consequences
and Remedies. Boca Raton, FL: CRC Press.

schaafsma, g. (2000). The protein digestibility-corrected amino acid score. Journal
of Nutrition, 130, 1865s–1867s.

schery, r. w. (1963). Plants for Man. Englewood Cliffs, NJ: Prentice Hall.
serna-saldivar, s. and rooney, l. w. (1995). Structure and chemistry of sorghum

and millets. In: dendy, d. a. v. (ed.) Sorghum and Millets: Chemistry and Technol-
ogy. St Paul, MN: AACC International, Inc.
shahidi, f. and chandrasekara, a. (2010). Content of insoluble bound phenolics in
millets and their contribution to antioxidant capacity. Journal of Agricultural and
Food Chemistry, 58, 6706–6714.
shahidi, f. and naczk, m. (1995). Food Phenolics Sources, Chemistry, Effects and
Application. Lancaster, PA, Basel: Technomic.
simic, m. g. and jovanovic, s. v. (1994). Teas, spices and herbs. In: ho, c.-t., osawa, t.,
huand, m.-t., rosen, r. t. (eds) Food Phytochemicals for Cancer Prevention II.
Washington DC: American Chemical Society.

© Woodhead Publishing Limited, 2013

Millet 349

singh, n., singh, j., kaur, l., sodhi, n. s. and gill, b. s. (2003). Morphological, thermal
and rheological properties of starches from different botanical sources. Food
Chemistry, 81, 219–231.

singh, k. p., mishra, a. and mishra, h. n. (2012). Fuzzy analysis of sensory attributes
of bread prepared from millet-based composite flours. LWT – Food Science and
Technology, 48, 276–282.

skovron, j. and lorenz, k. (1979). Enzymatic activities in proso millets. Cereal
Chemistry, 56, 559–562.

sridhar, r. and lakshminarayana, g. (1994). Contents of total lipids and lipid classes
and composition of fatty acids in small millets – foxtail (Setaria Italica), Proso
(Panicum Miliaceum), and finger (Eleusine coracana). Cereal Chemistry, 71,
355–359.

sun, z. and henson, c. a. (1990). Degradation of native starch granules by barley
alpha-glucosidases. Plant Physiology, 94, 320–327.

swain, r. r. and dekker, e. e. (1966). Seed germination studies. 2. Pathways for starch
degradation in germinating pea seedlings. Biochimica Et Biophysica Acta, 122,
87–100.

thiam, a. a. (1977). Contribution to the study of the biochemical phenomena of
millet and sorghum flour determination, Tropical Products Institute Conference
Papers. Dakar: Institut Technologie Alimentaire.

unido/fao (2007). Cereals Processing Toolkit. Available at: http://otp.unesco-ci.org/
fr/node/3609 [accessed December 2012].

usda (2012). Panicum miliaceum. United States Department of Agriculture Natural
Resources Conservation Service. Available at: http://plants.usda.gov/java/
profile?symbol=PAMI2 [accessed November 2012].

varrianomarston, e. and hoseney, r. c. (1983). Barriers to increased utilization of
pearl-millet in developing countries. Cereal Foods World, 28, 392–395.

vogel, s. and graham, m. (1979). Sorghum and millet: food production and use.
Report of a workshop held in Nairobi, Kenya, 4–7 July 1978. Ottawa: Centre de
recherche pour le développement international.

winch, t. (2006). Cereal. Growing Food. A Guide to Food Production. Dordrecht:
Springer.

world organisation for animal health, o. (2006). Guide to good farming practices
for animal production food safety. Review Science et Technique, 25, 823–836.

yamasaki, y. (2003). Beta-amylase in germinating millet seeds. Phytochemistry, 64,
935–939.

yamasaki, y. and konno, h. (1991). Purification and properties of alpha-glucosidase
from suspension-cultured sugar-beet cells. Phytochemistry, 30, 2861–2863.

yamasaki, y., konno, h. and masima, h. (1996). Purification and properties of alpha-
glucosidase from millet seeds. Phytochemistry, 41, 703–705.

yamasaki, y., fujimoto, m., kariya, j. and konno, h. (2005). Purification and charac-
terization of an [alpha]-glucosidase from germinating millet seeds. Phytochemis-
try, 66, 851–857.

yanez, g. a. and walker, c. e. (1986). Effect of tempering parameters on extraction
and ash of proso millet flours, and partial characterization of proso starch. Cereal
Chemistry, 63, 164–167.

yanez, g. a., walker, c. e. and nelson, l. a. (1991). Some chemical and physical-
properties of proso millet (Panicum milliaceum) starch. Journal of Cereal Science,
13, 299–305.

yeh, a. i. and li, j. y. (2001). Relationships between thermal, rheological character-
istics and swelling power for various starches. Journal of Food Engineering, 50,
141–148.

zarnkow, m., kessler, m., burberg, f., back, w., arendt, e. k. and kreisz, s. (2007).
The use of response surface methodology to optimise malting conditions of proso

© Woodhead Publishing Limited, 2013

350 Cereal grains for the food and beverage industries
millet (Panicum miliaceum L.) as a raw material for gluten-free foods. Journal of
the Institute of Brewing, 113, 280–292.

zarnkow, m., faltermaier, a., back, w., gastl, m. and arendt, e. k. (2010a). Evalua-
tion of different yeast strains on the quality of beer produced from malted proso
millet (Panicum miliaceum L.). European Food Research and Technology, 231,
287–295.

zarnkow, m., kessler, m., back, w., arendt, e. k. and gastl, m. (2010b). Optimisation
of the mashing procedure for 100 % malted proso millet (Panicum miliaceum L.)
as a raw material for gluten-free beverages and beers. Journal of the Institute of
Brewing, 116, 141–150.

ziegler, p. (1999). Cereal beta-amylases. Journal of Cereal Science, 29, 195–204.

© Woodhead Publishing Limited, 2013

10

Teff

DOI: 10.1533/9780857098924.351

Abstract: Teff [Eragrostis tef (Zuccagni) Trotter], is a tropical cereal. It is
considered a low-risk crop from the perspectives that it can be cultivated in a
broad range of ecological surroundings and under tough environmental
conditions where most other cereals fail. Teff is a major food crop in Ethiopia and
Eritrea, Africa, where it is mainly processed into different foods and beverages,
such as breads, sweet unleavened bread, porridges, pancakes, biscuits, cookies,
cakes, stir-fry dishes, casseroles, soups, stews and puddings. The teff kernel is
extremely small, perhaps the smallest amongst carbohydrate-rich grains, and it
represents an exceptional source of fibre and minerals, especially calcium and
iron. Due to its high fibre content and gluten-free status, teff is becoming a
popular ingredient in many countries for the production of gluten-free foods,
especially bakery products. In order to expand teff utilization in foods and
beverages worldwide, further research aims at improving crop production and
processing as well as addressing new methods for teff grain utilization.

Key words: teff, chemical composition, teff utilization in food and beverages.

10.1 Introduction

Teff [Eragrostis tef (Zuccagni) Trotter] is a tropical cereal also known as
‘tef’. It is a C4 self-pollinated plant (Kebede et al., 1989) producing a small-
grained cereal that has been grown as food crop in East Africa for thou-
sands of years (D’Andrea, 2008). In appearance, it is a fine stemmed, tufted
annual grass, which is adapted to a wide range of conditions including varied
rainfall levels, temperatures and soil regimes, and it is commonly grown
from near sea level to altitudes of over 3000 m (Seyfu, 1997). The common
vernacular name of the crop in Ethiopia is tef. It is also known by the col-
loquial name Tafi in Oromigna, which is another primary language of the
Ethiopian people and by Taf in Tigrigna, a third language of the Ethiopian
people (Seyfu, 1997; Alemayehu, 2001).

The use of teff can be traced back to about 3359 BC, with Ethiopia
having been recorded as the centre of origin (Mengesha, 1966) and domes-
tication of teff (Bultosa and Taylor, 2004). The word teff is thought to have
derived from the Ethiopian Amharic word teffa which means ‘lost’. This is

© Woodhead Publishing Limited, 2013

352 Cereal grains for the food and beverage industries

due to the small size of the grain and how easily it can be lost if dropped
(Gebremariam et al., 2012). Nowadays, teff represents a major food crop in
Ethiopia and Eritrea (Haileselassie et al., 2011) where it is mainly processed
into a fermented pancake-like, sour, circular, soft, spongy flat bread called
injera (Bultosa and Taylor, 2004).

It is an important cereal crop in Ethiopia, representing the second most
commonly produced crop (17.12 %) after maize (24.5 %), and is then fol-
lowed by sorghum (19.46 %) and wheat (14.03 %) (CSA, 2011). Outside
Ethiopia there is a growing interest in using teff. For example, small-scale
commercial production has begun in a few areas of the wheat belts in the
USA, Canada and Australia (Seyfu, 1997). Additionally, interest in teff has
also increased noticeably due to its gluten-free status and appealing nutri-
tional profile which make it a suitable wheat substitute for people with
coeliac disease (CD) (Zannini et al., 2012).

Because it is consumed as whole grain, teff has higher nutritive quality
than the other major cereal grains such as wheat, maize and barley (Belton,
2002). It typically contains 9.4–13.3 % protein, 73 % starch, 2.6–3.0 % ash
and 2.0–3.1 % lipid (Bultosa and Taylor, 2004; Gebremariam et al., 2012). It
is an excellent source of essential amino acids, especially lysine, the amino
acid that is most often deficient in grain foods.

In terms of chemical composition, 73 % of the whole kernel is composed
of starch, stored as polygonal starch granules in the endosperm section of
the grain (Bultosa and Taylor, 2004). Teff is also an exceptional source of
fibre and minerals, containing more calcium, iron, manganese and zinc than
most cereals. The absence of anaemia, particularly during pregnancy, in the
high teff consuming area of Ethiopia has been attributed to the generous
Fe levels in the Teff grain (Seyfu, 1997; Belton, 2002). Teff contains good
levels of vitamins A and C, as well as niacin (National Research Council,
1996), and their amount is generally increased by the yeast fermentation
process involved in the production of injera (National Research Council,
1996). Protein content is similar to that of other common cereals with
leucine, valine, proline, alanine and glutamic and aspartic acids being the
major amino acids. Teff grain is characterized by a lower fat content (2.0–
3.0 %) in comparison to maize and oats. However, its fatty acid composition
does not differ from the other cereal grains with palmitic, oleic and linoleic
acid being the major components.

In Ethiopia, teff flour use is far more widespread than its incorporation
into injera. It is also used to make porridge (muk), local alcoholic drinks
called tela and katikalla, as well as cakes and sweet dry unleavened bread
(kita) (National Research Council, 1996; Seyfu, 1997).

10.1.1 History, production area, price and yield
Few reports have been published on the early history of teff. Vavilov (1951)
recorded Ethiopia as its centre of origin, and it is clear that teff is indigenous

© Woodhead Publishing Limited, 2013

Teff 353

to that area, but the exact details of its domestication are unclear.According
to Ponti (1978), teff is believed to have first been domesticated in Ethiopia
well before the Semitic invasion of 1000–4000 BC. It was probably culti-
vated in Ethiopia even before the ancient introduction of emmer and barley
(Tadesse, 1975). Teff seeds found in the Pyramid of Dashur built in 3359 BC
(Unger, 1866) and from the ancient Jewish town of Ramses, Egypt built in
1400–1300 BC were probably E. aegyptiaca or E. pilosa and thus are not
good evidence for the cultivation of teff in ancient Egypt.

There is no official data from the FAO database regarding world or
country-specific production levels for teff. Ethiopia is the only country in
the world that uses teff as a cereal crop, with the USA using it as a health
grain and South Africa as a forage crop. According to data collected over
an 11-year period (2000–2011) from the Central Statistics Authority, teff is
annually cultivated on about 2.3 million hectares of land (Table 10.1). Its
cultivation area has been expanding over time and shows an increase of
8.2 % from 2000 to 2011. In Table 10.1, it is interesting to notice that the
increase in teff production, equal to 27.6 %, in the last 11 years, is due only
in part to the increased cultivation area and, in fact, mainly to the rise of
teff yield by 35.81 %.

Nowadays in Ethiopia, teff is cultivated on about 2.76 × 106 ha and occu-
pies about 23.35 % of the total crop area allocated to cereals (CSA, 2011),
delivering about 17.12 % (3.48 × 106 tonnes) of the total grain production
nationally (CSA, 2011). Its production is crucial for national food security.
The average teff grain yield of 1.26 tonnes/ha is lower compared to other
cereal grains; however, using improved cultivars and management practices,
it is possible to obtain yields up to 2.5 tonnes/ha (Haileselassie et al., 2011)
and the yield potential under optimal management is as high as 4.5 tonnes/
ha (Teklu and Tefera, 2005).

Teff has attracted much interest in the international market (Spaenij-
Dekking et al., 2005) because it is a gluten-free food crop grown predomi-
nantly by small-holders. It is given a high market value because it is in high
demand, meaning that farmers earn more from growing teff than growing
other staple crops (Araya et al., 2010b). During the last decade, teff prices
have increased between 30 and 36 %, depending on the type of teff (red,
white or mixed) (Table 10.1). However, in the production year 2009, regard-
less of which type, the price of teff increased dramatically by up to 35 %
with respect to the market prices recorded in 2008 (Table 10.1).

10.1.2 Phytology, classification and cultivation
Teff belongs to the family Poaceae, sub-family Eragrostoideae, Tribe Era-
grostae and genus Eragrostis. There are approximately 300 species (Cos-
tanza, 1974) in the genus Eragrostis consisting of both annuals and perennials
which are found over a wide geographic range. Teff is a C4 self-pollinated
allotetraploid cereal plant with a chromosome number of 2n = 4x = 40. It

© Woodhead Publishing Limited, 2013

354 Cereal grains for the food and beverage industries

Table 10.1 Cultivation area, yield, production and market price of teff from
2000–2011

Year Total teff Area teff Teff yield Market pricea (USD/t)
production harvested (t/ha) White teff Mixed teff Red teff
(Mt) (Mha)

2000 1.71 2.12 0.81 291.5 272.7 223.6
2001 1.73
2002 1.65 2.18 0.79 266.2 243.9 190.5
2003
2004 – 1.90 0.87 213.8 182.3 128.5
2005 1.67
2006 2.02 – – 284.3 259.8 229.5
2007 2.17
2008 2.43 1.99 0.84 263.3 235.4 192.5
2009 2.99
2010 3.02 2.13 0.95 304.8 284.6 219.6
2011 3.18
2012 3.48 2.24 0.97 364.2 339.78 280.7
Average
– 2.40 1.01 473.3 439.3 361.3
2.37
2.56 1.17 503.0 473.4 377.9

2.48 1.22 826.6 772.4 583.5

2.59 1.23 699.6 627.8 465.9

2.76 1.26 460.7 393.9 335.1

– – 566.7 507.3 446.2

2.30 1.01 424.4 387.1 310.3

aMarket price of Teff recorded to the first month of the year and referred at the Addis Ababa
market (2012) (http://egtemis.com/marketstat.asp).
Source: Data from CSA (2011).

has a fibrous root system with mostly erect stems, although some cultivars
are bending or elbowing types. The inflorescence is an open panicle showing
different forms, from loose to compact, and can produce up to 50 000 grains
(Bultosa and Taylor, 2004). Teff has adapted to dry-land farming in Ethiopia
and is considered to be a drought-resistant crop. However, the major yield-
limiting factor in teff production, which provides obstacles to its develop-
ment into sustainable agriculture, is seasonal crop water shortage (Araya
et al., 2010b). Generally, most teff cultivars require at least three good rains
during their early growth and a total of 200–300 mm of water (National
Research Council, 1996). It is particularly valued in areas which are too cold
for sorghum or maize. However, while teff has some frost tolerance, it will
not survive a prolonged freeze. In contrast, it can tolerate temperatures (at
its lower altitudinal range) well above 35 °C (National Research Council,
1996).

Teff is not normally sown until the peak of the rainy period. Wet sowing
is preferred to avoid a false start, to improve seedling establishment and to
reduce shoot fly infestation (Araya et al., 2010a). Teff seeds are sown on the
surface of the soil and left uncovered or sometimes covered very lightly
by pulling woody tree branches over the field (Seyfu, 1997). Sowing can
be performed by hand or motor-driven broadcasting. About 15–55 kg
of teff seeds are sown per hectare under different conditions. If sowing
is performed by hand-broadcasting, a seed rate of 40–50 kg per hectare is

© Woodhead Publishing Limited, 2013

Teff 355

recommended, due to the small seed size (l000-seed weight is only 265 mg)
while, if a motor-driven broadcaster or drill is available, a lower seed rate
(about 15 kg/ha) is adequate (Seyfu, 1997).

Teff requires little care once it is established. It has fewer disease and
pest problems in the field as compared to maize, sorghum, wheat or barley
(Stewart and Dagnachew, 1967), and its rapid growth stifles most weeds.
Teff productivity is good enough without having to supplement with nutri-
ents; however, in most places, it will respond to fertilizers. Nitrogen (N) and
phosphorus (P) fertilization are key elements when improving straw and
grain production, respectively (Seyfu, 1997). Beside these macronutrients,
Haileselassie et al. (2011) showed that Zn represents a yield-limiting factor
in teff production on vertisols (dark, montmorillonite-rich clay soils with
characteristic shrinking and swelling properties). In particular, the studies
show that on-farm application of Zn fertilizer at a rate of 8 kg Zn/ha gener-
ally increases teff grain and straw yields by 14 % and 15 % on average,
respectively, which could be economically profitable.

Teff is harvested when the vegetative parts turn yellowish or a straw-like
colour (generally between 60 to 160 days, depending on the maturity period
of the varieties)(Bultosa and Taylor, 2004). In comparison with other cereals,
teff grain is less susceptible to attacks by weevils or other storage pests and,
thus, chemicals are not required to control storage pests. This means that
teff seed can be stored very easily for several years under local storage
conditions (Seyfu, 1997; Bultosa and Taylor, 2004).

10.1.3 Structure of the teff kernel
The teff kernel is extremely small, perhaps the smallest among carbohydrate-
rich kernels, (Bultosa et al., 2002) with 2500–3000 grains weighing about 1 g
(Babatunde Obilana and Manyasa, 2002). The kernels are hull-less (naked)
and can be characterized by different colours – netch (white), qey (red/
brown) and sergegna (mixed) (Tefera et al., 1995). The colour in red teff
varieties is due to the high content of polyphenol and/or tannins. White teff
is the most expensive and preferred type, but it only grows in certain regions
of Ethiopia. The red teff is the least expensive, reputed for its high iron
content and is the most common in the Egyptian market. The brown teff is
known for its moderate iron content (El-Alfy et al., 2011).

The outermost structure of the kernel is termed pericarp (Fig. 10.1),
represented by a thin membranous layer containing some starch granules.
Beneath the pericarp is a seed coat, or testa, which in red teff varieties
contains polyphenols or tannin, and is responsible for the red colour of the
teff kernel. Next to the testa is the aleurone layer which is particularly rich
in protein and lipid bodies.The endosperm represents the major component
of the grain and, as in other tropical cereals, comprises an outer vitreous
layer. This contains most of the protein of the kernel and a few starch gran-
ules and has an inner floury part which contains mainly starch granules with

© Woodhead Publishing Limited, 2013

356 Cereal grains for the food and beverage industries

Pericarp Starchy endosperm
Embryo Corneous endosperm

×70 200 μm

Fig. 10.1 Scanning electron microscope (SEM) micrographs representative of teff
kernel in longitudinal cross-section.

a few protein bodies (Fig. 10.1 and Plate VII – see colour section between
pages 230 and 231). The embryo, which constitutes the living part of the teff
kernel, occupies a relatively large proportion of the grain and is rich in
protein and lipid bodies (Babatunde and Manyasa, 2002; Bultosa and Taylor,
2004) (Fig. 10.2).

10.2 Chemical composition of the teff kernel

Polysaccharides, proteins and lipids represent the three major constituents
of the teff kernel. The typical teff kernel is composed of 73 % starch, 11 %
protein, 2.5 % lipid and 2.8 % ash (Table 10.2), supplying approximately
367 kcal/100 g of grain (USDA, 2011). Teff has a protein content compa-
rable to that of other cereals such as barley and wheat, and higher than that
of sorghum, rye and brown rice (Gebremariam et al., 2012).

© Woodhead Publishing Limited, 2013

Teff 357

200.0 μm
Fig. 10.2 Confocal laser scanning microscope (CLSM) micrograph of longitudinal

section of teff kernel with the germ and endosperm.

10.2.1 Carbohydrates
The main chemical constituents of the teff caryopsis are carbohydrates.
They are present in different tissues of the teff kernel. Among the carbo-
hydrates present, starch is the major component (73 % of the kernel dry
weight) and is mainly concentrated in the endosperm (Bultosa and Taylor,
2004).
Starch
Starch granules in teff are conglomerates of many polygonal simple gran-
ules (Bultosa et al., 2002) (Fig. 10.3) and are very small (2–6 μm in diame-
ter). However, they are larger in size compared to amaranth and quinoa
and similar to rice starch granules (Bultosa et al., 2002). As observed in
other cereal grains, starch granules are mainly composed of a branched
fraction, amylopectin, and a linear fraction, amylose, which latter makes up
25–30 % of starch. Gelatinization temperature of raw teff (68–80 °C) is
similar to that of other tropical cereal starches like sorghum (67–81 °C), but
occurs over a narrower temperature range than that of maize (60–79 °C)
(Gebremariam et al., 2012). The teff starch pasting temperature is similar
to that of maize starch, but the cooking time for peak viscosity is longer.
Peak, breakdown and setback viscosities are lower than those of maize
starch (Bultosa and Taylor, 2004). Due to the smooth, very small and
uniform size of its granules, teff starch offers good functionality as a flavour
and aroma carrier or fat replacer.

© Woodhead Publishing Limited, 2013

358 Cereal grains for the food and beverage industries

Table 10.2 Composition of teff grains

Components (g) Value per 100 g

Water 8.82
Energy (Kcal) 367
Protein 11.1
Total lipid (fat)
Carbohydrate 2.38
Fibre, total dietary 73.13
Sugars, total 8
1.84
Total lipid (g)
Fatty acids, total saturated 0.449
Fatty acids, total monounsaturated 0.589
Fatty acids, total polyunsaturated 1.071

Minerals (mg) 180
Calcium 7.63
Iron
Magnesium 184
Phosphorus 429
Potassium 427
Sodium 12
Zinc
3.63
Vitamins
Thiamin (mg) 0.39
Riboflavin (mg) 0.27
Niacin (mg) 3.363
Vitamin B6 (mg) 0.482
Vitamin A (IU) 9
Vitamin E (α-tocopherol) (mg) 0.08
Vitamin K (phylloquinone) (μg) 1.9

Source: Adapted from USDA/ARS (2012).

10.2.2 Protein
Protein is the second most abundant component in teff after starch. It
ranges between 8.7 and 11 % with a mean of 10.4 % (Bultosa, 2007). Thus,
the protein content of the teff grain is comparable to that of other common
cereals such as barley, wheat, maize and pearl millet (Gebremariam et al.,
2012). Glutelins and albumins are the major storage protein components
representing 44.55 and 36.6 % of the total protein storage in teff, respec-
tively. These two protein fractions are also recognized as the most digestible
types, thus ensuring that protein digestibility is correspondingly high (Baba-
tunde Obilana and Manyasa, 2002). The teff prolamin fraction (11.8 %) is
lower than in most other cereals, except in rice and oats (Tatham et al., 1996;
Bultosa and Taylor, 2004).

The most abundant amino acids are glutamic acid, alanine, proline, aspar-
tic acid, leucine and valine (Table 10.3). Methionine, alanine and histidine

© Woodhead Publishing Limited, 2013

Teff 359

5 kV ×1,000 10 μm AMRF, UCC

Fig. 10.3 SEM micrograph of fractured endosperm showing polygonal shape
starch granules.

Table 10.3 Amino acid composition (g/ 16.8 g N) of teff compared with other
cereal grains rice and milled rice

Amino acids (g/ 16.8 g N) Teff Wheat Rice Sorghum Barley

Alanine 10.1 3.5 5.5 1.5 4.5
0.6 4.7
Arginine 5.1 3.5 8.5 – 4.6
0.3 2.2
Asparagine + aspartic acid 6.4 5.1 9.0 – 18.8
0.5 3.3
Cysteine 2.5 2.4 1.8 0.3 2.1
0.6 3.6
Glutamine + glutamic acid 21.8 29.5 17.0 2.1 6.7
0.3 3.4
Glycine 3.1 4.0 4.5 0.3 1.7
0.9 5.1
Histidine 3.2 2.1 2.3 1.3 9.6
0.8 3.5
Isoleucine 4.1 3.7 4.5 0.5 3.3
0.2 1.5
Leucine 8.5 7.0 8.2 0.7 3.1
0.8 5.0
Lysine 3.7 2.0 3.7

Methionine 4.1 1.5 2.7

Phenylalanine 5.7 4.9 5.5

Proline 8.2 10.1 5.0

Serine 4.1 5.0 5.0

Threonine 4.3 2.7 3.7

Tryptophan 1.3 1.1 1.2

Tyrosine 3.8 2.3 5.2

Valine 5.46 4.1 6.0

Source: Gebremariam et al. (2012).

contents are slightly higher than in most other cereals, but serine and
glycine are lower. Teff combines a good content and balance of essential
amino acids; however, as with many cereals, lysine represents its first limit-
ing amino acid (Jansen et al., 1962) (Table 10.4). The overall amino acid
profile of teff can be regarded as being well-balanced.

© Woodhead Publishing Limited, 2013

360 Cereal grains for the food and beverage industries

Table 10.4 Essential amino acid content of teff as compared with the FAO/WHO
Human Nutritional Requirements

Amino acid (g/kg of protein) Teff EEA daily childhood
requirementsa

Lysine 14–40 45
Threonine 24–44 23
Valine 41–99 39
Cysteine + methionine 25–71 22
Isoleucine 40–50 30
Phenylalanine + tyrosine 45–99 38
Tryptophan 13–15 13

aFAO/WHO (2002).
Sources: Adapted from Bultosa and Taylor (2004), Seyfu (1997), Gebremariam et al. (2012).

10.2.3 Lipids
Teff grain contains lower levels of lipids (approximately 2.0–3.0 % of total
grain weight) when compared to other cereals such as maize (4.9 %), oats
(6.9 %), millet (4.2 %) and sorghum (3.4 %) (Weber, 1987). Its crude fat
consists mostly of non-starch lipids. In fact, the lipid content of the teff
starch (mean 0.29 %) is relatively low when compared to that of maize
starch (0.34 %) (National Research Council, 1996).

Teff grains are rich in unsaturated fatty acids (72.46 %), among which
39.91 % were polyunsaturated and 20.06 % were saturated fatty acids
(El-Alfy et al., 2011). As in most other cereal grains, oleic (32.41 %), linoleic
(23.83 %) and palmitic (15.9 %) acids are the major fatty acids (El-Alfy
et al., 2011). Linolenic acid levels are higher in teff than in maize, sorghum,
and wheat (Bultosa and Taylor, 2004).

10.2.4 Dietary fibre
The fibre content of teff (3 % dry basis) is particularly high and exceeds
that of most other cereals, such as wheat (2 % dry basis), rye (1.5 % dry
basis), rice (0.6–1.0 % dry basis) and sorghum (0.6 % dry basis) (Gebre-
mariam et al., 2012). Its higher fibre content is due to the fact that teff is
always consumed in the whole-grain form (bran and germ included), since
it is impossible to perform any fractionation during the milling process due
to the small size of teff grains (Bultosa and Taylor, 2004).

10.2.5 Vitamins
Teff contains good levels of certain vitamins such as vitamin C, vitamin B3
(niacin), vitamin B2 (riboflavin), vitamin B1 (thiamine) and vitamin A
(National Research Council, 1996) (Table 10.2). However, thiamin in teff is

© Woodhead Publishing Limited, 2013

Teff 361

typically lower when compared to other cereal grains such as wheat, rye,
barley, oats, rice, maize, millet and sorghum. In contrast, vitamin C is rela-
tively adequate, providing more than 100 % of the recommended dietary
allowance (Babatunde Obilana and Manyasa, 2002).

10.2.6 Minerals
Teff mineral contents range from 2.8–3.4 % (Babatunde Obilana and
Manyasa, 2002; Bultosa and Taylor, 2004). As such, in addition to providing
protein and calories, teff is a good source of minerals (Table 10.2), particu-
larly Fe, resulting in a mineral content approximately two to three times
that of wheat, barley and sorghum (Mengesha, 1966). Generally, the whole
grain of teff is ground into flour, with most of the Fe found in the seed being
retained in the flour and, subsequently, in the food. Moreover, destruction
of phytic acid by fermentation is known to contribute to high Fe availability
in diets (Adams, 1990) and, additionally, fermented teff foods are the staple.
This explains the low frequency of anaemia in the highlands of Ethiopia,
where teff represents the first cereal crop (Mengesha, 1966; Gebremariam
et al., 2012). Teff also contains high levels of Ca, P, Cu, Zn and Mg (Seyfu,
1997; Bultosa and Taylor, 2004).

10.2.7 Phytochemicals
Phytochemicals are non-nutritive components present in plants that exert
protective or disease-preventing effects in the diet. Several studies have
reported the antioxidant and anticarcinogenic effects of white corn poly-
phenol such as ferulic and p-coumaric acids along with their respective
derivatives (Andreasen et al., 2001; Anselmi et al., 2004; Trombino et al.,
2004). In teff, the major phenolic compound is represented by ferulic
acid (285.9 μg/g). Additionally, some other phenolic compounds such as
syringic (14.9 μg/g), gentisic (15 μg/g), protocatechuic (25.5 μg/g), vanillic
(54.8 μg/g), coumaric (36.9 μg/g) and cinnamic (46 μg/g) acids are also
present in teff in considerable amounts (Blandino et al., 2003; Firew, 2010).

10.3 Teff milling and applications in foods and beverages

Teff can be milled and the resulting flour used to make traditional breads
such as injera or incorporated into other bakery products as well as a
number of alcoholic beverages.

10.3.1 Milling
Teff grains are cleaned and dry-milled using indigenously developed
methods and equipment to obtain whole flour. Traditionally, teff is ground

© Woodhead Publishing Limited, 2013

362 Cereal grains for the food and beverage industries

into flour using either attrition or a hammer mill in a small-scale batch
process run by electrical power. If this is not available, the process will be
run by a diesel engine or water power. Teff grains are ground between a
pair of horizontally placed millstones. The lower or bed stone is fixed to the
floor of the milling room and the upper stone rotates on a central axis. The
grain is poured into a central hole (the eye) in the middle of the upper
stone. In this way, the grain is positioned centrally between the two mill-
stones and is then fragmented and ground between them, with the flour
being expelled at the periphery (Babatunde Obilana and Manyasa, 2002;
Bultosa and Taylor, 2004).

Food made from teff grain is a staple diet for many Ethiopians. Teff in
the form of flour is typically used to make various products, such as breads,
sweet unleavened bread, porridges (genfo; stiff porridge, and atmit; thin
porridge/gruel), pancakes, biscuits, cookies, cakes, stir-fry dishes, casseroles,
soups, stews and puddings (Bultosa and Taylor, 2004).

10.3.2 Bakery products from teff
Teff flour is mainly used to make injera (a popular fermented flat bread), kitta
(sweet flat bread), chibito (unleavened kitta that is rolled like a ball) and
anebabro (two leavened kitta, placed one on top of the other during baking)
(Firew, 2010). For producing injera, teff flour is mixed with water in a 1 :1 ratio
and kneaded to form dough. The dough is covered and allowed to ferment
for two to three days. Microorganisms involved in the fermentation of injera
are lactic acid bacteria (LAB), which belong to the genera Leuconostoc,
Streptococcus, Pediococcus and Lactobacillus, yeasts, which belong to the
general Saccharomyches, Torulopsis and Candida, and fungi, including Pul-
laria, Aspergillus, Penicillium (Steinkraus, 1986; Abdel Gadir et al., 1996;
Bultosa and Taylor, 2004).The fermentation can start spontaneously by com-
mensal microorganisms, or it can be initiated by the addition of starter cul-
tures from previous batch fermentations, which are locally called irsho/
raacitii. A portion of the dough (5 %) is taken to mix with water. This slurry
is then cooked to make warm gruel that is subsequently added back to the
dough and thoroughly mixed. The slurry acts as a binder, due to its higher
content of gelatinized starch, thus improving the viscosity and gas-holding
capacity of the dough in the subsequent fermentation step. Extra water is
added into the dough again to make a batter which is allowed to stand for
2–3 h. Afterwards, the batter is poured onto a hot-round smooth griddle,
which was previously swabbed with ground oilseeds or with animal fat to
prevent the injera from sticking to the surface. It is then covered with a metal
lid to prevent steam from escaping. Within about 2–3 min it is ready to be
removed from the pan and is then placed on a basket (Babatunde Obilana
and Manyasa, 2002; Bultosa and Taylor, 2004). The storage period does not
usually exceed three days at room temperature (Blandino et al., 2003).

© Woodhead Publishing Limited, 2013

Teff 363

A typical injera is round, soft, spongy and resilient, about 6 mm thick,
60 cm in diameter and weighs between 250 and 700 g, depending on the
thickness of the batter and the type of flour used, with uniformly spaced
honeycomb-like ‘eyes’ on the top (Gebrekidan and Gebrettiwat, 1982). The
major quality attribute of a good injera is its slightly sour flavour. Injera has
a very high nutritional value, as it is rich in calcium and iron (Zegeye, 1997).
Generally injera is eaten with a meat, vegetable or legume stew called wot
(wat). It may also be eaten alone, simply dipped into salt, garlic salt, awaze,
a spice called berberi or a mixture of salt, red pepper, coriander and other
spices.

Consumer awareness of the health benefits of whole grains has led to a
growing demand for healthier cereal products by incorporating into their
diet some less utilized and ancient grains, such as millet, quinoa, sorghum
and teff. The latter has the potential to be used in bakery products due to
its positive physico-chemical properties, such as the high fibre (National
Research Council, 1996; USDA/ARS, 2012) and mineral (iron, calcium and
zinc) content (Abebe et al., 2007), as well as the slow retrogradation ten-
dency of its starch (Bultosa et al., 2002), leading to an improved shelf-life
of its baked products.

However, the incorporation of teff into bread is a challenging task for
cereal technologists because it does not contain gluten network-forming
proteins, which are essential for producing leavened bread with a fine open
structure. Generally, increasing the level of teff in the bread formulation
significantly increased dough development time, degree of softening, crumb
firmness and bitter flavour, whilst decreasing the dough stability, specific
loaf volume and overall acceptability of the bread (Alaunyte et al., 2012).
Different attempts were made to incorporate teff into straight dough bread-
making (Ben-Fayed et al., 2008; Mohammed et al., 2009). In all cases, addi-
tion of teff in the range between 20 and 30 % had a detrimental effect on
quality of breads in terms of specific volume and crumb firmness (Ben-
Fayed et al., 2008; Mohammed et al., 2009). However, only 5–10 % teff-
containing breads had comparable acceptability scores to wheat bread
(Ben-Fayed et al., 2008; Mohammed et al., 2009).

In order to overcome these adverse effects of teff flour in bread recipes,
a number of different enzymes and sourdough technology have been
used. Alaunyte et al. (2012) showed that teff breads, produced using
straight dough and sourdough bread-making, with the addition of different
enzyme combinations (xylanase and α-amylase, α-amylase and glucose
oxidase, glucose oxidase and xylanase, as well as lipase and α-amylase)
showed substantial enhancements in terms of loaf volume, crumb firmness,
crumb structure, flavour and overall acceptability of the bread. Renzetti
et al. (2008) investigated the potential network-forming ability of trans-
glutaminase (TGase) in six different gluten-free cereals (brown rice, buck-
wheat, corn, oat, sorghum and teff) for use in bread-making. Regarding

© Woodhead Publishing Limited, 2013

364 Cereal grains for the food and beverage industries

teff, the authors concluded that the addition of TGase, up to 10 U/g of
proteins present in the recipe, didn’t affect the dough and bread quality
parameters.

Sourdough technology was also proposed as a natural, low-cost and
efficient technology to improve the bread-making performance of gluten-
free bread including teff (Moroni et al., 2009). In this regard, the same
authors (Moroni et al., 2010, 2011) developed teff sourdough using either
spontaneous fermentation or starter cultures. They detected unique and
complex LAB and yeast communities. The LAB Lactobacillus pontis, L.
reuteri, L. fermentum and L. helveticus and yeasts Kazachstania barnetti,
Saccharomyces cerevisiae and Candida glabrata were found to dominate the
teff sourdoughs, suggesting their potential use as starters for the production
of sourdough destined for gluten-free bread production. Additionally, teff
sourdough LAB can also improve the microbial stability of teff dough by
inhibiting pathogen/spoilage microorganisms like Salmonella spp., Pseudo-
monas aeruginosa, Klebsiella spp., Bacillus cereus and Staphylococcus
aureus (Nigatu and Gashe, 1994).

10.3.3 Alcoholic beverages
In Ethiopia, teff grain is also used to make traditional alcoholic beverages
such as tella (traditional opaque beer of low alcohol content), katikala/arake
and shamit (spirit) all produced at a household level. Tella has a smoky
flavour due to the addition of burned bread. In the production of tella,
leaves of Gesho (Rhamnus prinoides) impart characteristic bitterness into
the beverage while, at the same time, regulating the microflora responsible
for the fermentation process (Kleyn and Hough, 1971). The alcoholic
content of tella ranges between 2 and 4 % by vol. However, filtered tella
can reach a higher alcoholic content (5–6 % by vol) (Selinus, 1971). Talla
or tella, a home-based beer from Ethiopia, is traditionally served at wedding
ceremonies (Vogel and Gobezie, 1996).

Arake is a distilled beverage (45–50 % by vol) produced by mixing
ground gesho-leaves and water (kept for three to four days) with unleav-
ened bread (kita) made of teff or other cereals, and germinated barley or
wheat. The mixture is fermented for five to six days and then distilled
(Selinus, 1971).

Shamit is a widely consumed low-alcohol, local beer, with a thick consis-
tency. For its preparation, unleavened teff bread, called kita, and germinated
barley, called bekel, are milled and mixed with water with subsequent
filtration after three to four days of fermentation. The microorganisms
responsible for the fermentation, consisting of mainly LAB and yeasts
(Mogessie and Tetemke, 1995), come mostly from back-slopping, using
a small amount of shamita from a previous fermentation, as well as
from ingredients and equipment. The dominant lactic flora consisted of
both heterofermentative and homofermentative lactobacilli. The pH of

© Woodhead Publishing Limited, 2013

Teff 365

fermenting shamita dropped from an initial value of 5.80 to 4.43 within
12 hs of fermentation (Mogessie, 2006).

10.4 Conclusions

Teff can be grown in areas experiencing moisture stress and waterlogged
conditions with relatively few pest- and disease-related problems in the field
and during storage. The nutritional quality of teff grains indicates that it has
potential for interesting applications in the development of a wide range of
food and beverages considering its status as a gluten-free grain and its very
high mineral content, especially calcium and iron.

10.5 Future trends

Due to the unique qualities of teff, which is able to flourish in a broad
ecological range and tolerate harsh environmental conditions, its potential
expansion in every part of the world represents a real prospect and a par-
ticularly appealing solution for many nations experiencing moisture stress
conditions. Key elements to promote worldwide teff utilization in foods and
beverages include: (i) development of suitable and efficient breeding or
biotechnology techniques to maximize the grain production; (ii) improve-
ment of agricultural practices; and (iii) development of more suitable
milling technology and extraction procedures (e.g. for starch extraction). A
strategic approach which is able to integrate all of the aforementioned key
factors is essential for overcoming present constraints.

10.6 References

abdel gadir, a. m. et al. (1996). Indigenous fermented foods involving an acid fer-
mentation: preserving and enhancing organoleptic and nutritional qualities of
fresh foods. In: steinkraus, k. h. (ed.) Handbook of Indigenous Fermented Foods
(2nd edn). New York: Marcel Dekker, 111–348.

abebe, y., bogale, a., hambidge, k. m., stoecker, b. j., bailey, k. and gibson, r. s. (2007).
Phytate, zinc, iron and calcium content of selected raw and prepared foods con-
sumed in rural Sidama, Southern Ethiopia, and implications for bioavailability.
Journal of Food Composition and Analysis, 20, 161–168.

adams, m. r. (1990). Topical aspects of fermented foods. Trends in Food Science &
Technology, 1, 140–144.

alaunyte, i., stojceska, v., plunkett, a., ainsworth, p. and derbyshire, e. (2012).
Improving the quality of nutrient-rich Teff (Eragrostis tef) breads by combination
of enzymes in straight dough and sourdough breadmaking. Journal of Cereal
Science, 55, 22–30.

alemayehu, r. (2001). TEF: Post-harvest Operations. Addis Ababa: Institute of Agri-
cultural Research Organization, Holetta Agricultural Research Center (IARO).

© Woodhead Publishing Limited, 2013

366 Cereal grains for the food and beverage industries

andreasen, m. f., kroon, p. a., williamson, g. and garcia-conesa, m. t. (2001). Ester-
ase activity able to hydrolyze dietary antioxidant hydroxycinnamates is distrib-
uted along the intestine of mammals. Journal of Agricultural and Food Chemistry,
49, 5679–5684.

anselmi, c., centini, m., granata, p., sega, a., buonocore, a., bernini, a. and facino,
r. m. (2004). Antioxidant activity of ferulic acid alkyl esters in a heterophasic
system: A mechanistic insight. Journal of Agricultural and Food Chemistry, 52,
6425–6432.

araya, a., keesstra, s. d. and stroosnijder, l. (2010a). A new agro-climatic classifica-
tion for crop suitability zoning in northern semi-arid Ethiopia. Agricultural and
Forest Meteorology, 150, 1057–1064.

araya, a., keesstra, s. d. and stroosnijder, l. (2010b). Simulating yield response to
water of Teff (Eragrostis tef) with FAO’s AquaCrop model. Field Crops Research,
116, 196–204.

babatunde obilana, a. and manyasa, a. (2002). Millets. In: belton, p. s. and taylor,
j. r. (eds) Pseudocereals and Less Common Cereals. Berlin: Springer-Verlag.

belton, s. p. (2002). Pseudocereals and Less Common Cereals: Grain Properties and
Utilization Potential. Berlin: Springer.

ben-fayed, e., ainsworth, p. and stojceska, v. (2008). The incorporation of Teff
(Eragrostis tef) in bread-making technology. Cereal Food World, 53, A84.

blandino, a., al-aseeri, m. e., pandiella, s. s., cantero, d. and webb, c. (2003).
Cereal-based fermented foods and beverages. Food Research International, 36,
527–543.

bultosa, g. (2007). Physicochemical characteristics of grain and flour in 13 tef
(Eragrostis tef (Zucc.) Trotter) grain varieties. Journal of Applied Sciences
Research, 3, 2042–2051.

bultosa, g. and taylor, j. r. n. (2004). TEFF. In: wrigley, c., corke, h. and walker,
c. (eds) Encyclopedia of Grain Science. Oxford: Elsevier.

bultosa, g., hall, a. n. and taylor, j. r. n. (2002). Physico-chemical characterization
of grain tef [Eragrostis tef (Zucc.) Trotter] starch. Starch, 54, 461–468.

costanza, s. h. (1974). Literature and numerical taxonomy of tef (Eragrostis tef),
MSc thesis, Cornell University, Ithaca, NY.

csa (2011). Agricultural Sample Survey 2010/2011. Volume 1, Area and Production
Crops. Addis Ababa: Central Statistical Agency.

d’andrea, a. (2008). T’ef (Eragrostis tef) in ancient agricultural systems of highland
Ethiopia. Economic Botany, 62, 547–566.

el-alfy, t. s., ezzat, s. m. and sleem, a. a. (2011). Chemical and biological study
of the seeds of Eragrostis tef (Zucc.) Trotter. Natural Product Research, 26,
619–629.

fao/who (2002). Protein and amino acid requirements in human nutrition. WHO
Technical Report Series No.935. Geneva: Joint FAO/WHO/UNU Expert
Consultation.

firew, g. a. (2010). Cultivation and consumption of teff in Gojjam Highlands: impli-
cation for understanding the beginning of food production in Ethiopia. NYAME
AKUMA, 73, 77–87.

gebrekidan, b. and gebrettiwat, b. (1982). Sorghum injera: preparation and quality
parameters, In: Proceedings of the International Symposium on Sorghum Grain
Quality. Patancheru: ICRISAT, 55–56.

gebremariam, m., zarnkow, m. and becker, t. (2012). Teff (Eragrostis tef ) as a
raw material for malting, brewing and manufacturing of gluten-free foods
and beverages: a review. Journal of Food Science and Technology, DOI
10.1007/s13197-012-0745-5.

haileselassie, b., stomph, t.-j. and hoffland, e. (2011). Teff (Eragrostis tef ) produc-
tion constraints on Vertisols in Ethiopia: farmers’ perceptions and evaluation

© Woodhead Publishing Limited, 2013

Teff 367

of low soil zinc as yield-limiting factor. Soil Science and Plant Nutrition, 57,
587–596.
jansen, g. r., dimaio, l. r. and hause, n. l. (1962). Cereal proteins, amino acid com-
position and lysine supplementation of teff. Journal of Agricultural and Food
Chemistry, 10, 62–64.
kebede, h., johnson, r. c. and ferris, d. m. (1989). Photosynthetic response of
Eragrostis tef to temperature. Physiologia Plantarum, 77, 262–266.
kleyn, j. and hough, j. (1971). The microbiology of brewing. Annual Review of
Microbiology, 25, 583–608.
mengesha, m. h. (1966). Chemical composition of teff (Eragrostis Tef ) compared
with that of wheat, barley and grain sorghum. Economic Botany, 20, 268–273.
mogessie, a. (2006). A review on the microbiology of indigenous fermented food
and beverages of Ethiopia. Ethiopian Journal of Biological Sciences, 5, 189–245.
mogessie, a. and tetemke, m. (1995). Some microbiological and nutritional proper-
ties of ‘Borde’ and ‘Shamita’, traditional Ethiopian fermented beverages. Ethio-
pian Journal of Health Development, 9, 105–110.
mohammed, m. i. o., mustafa, a. i. and osman, g. a. m. (2009). Evaluation of wheat
breads supplemented with teff (Eragrostis tef (zucc.) trotter) grain flour. Austra-
lian Journal of Crop Science, 3, 207–212.
moroni, a. v., dal bello, f. and arendt, e. k. (2009). Sourdough in gluten-free bread-
making: An ancient technology to solve a novel issue? Food Microbiology, 26,
676–684.
moroni, a. v., arendt, e. k., morrissey, j. p. and bello, f. d. (2010). Development of
buckwheat and teff sourdoughs with the use of commercial starters. International
Journal of Food Microbiology, 142, 142–148.
moroni, a. v., arendt, e. k. and bello, f. d. (2011). Biodiversity of lactic acid bacteria
and yeasts in spontaneously-fermented buckwheat and teff sourdoughs. Food
Microbiology, 28, 497–502.
national research council (1996). Lost Crops of Africa. Washington DC: National
Academies Press.
nigatu, a. and gashe, b. a. (1994). Inhibition of spoilage and food-borne pathogens
by lactic-acid bacteria isolated from fermenting tef (Eragrostis tef ) dough. Ethio-
pian Medical Journal, 32, 223–229.
ponti, j. a. (1978). The systematics of Eragrostis tef (Graminae) and related species,
PhD thesis, University of London, London.
renzetti, s., dal bello, f. and arendt, e. k. (2008). Microstructure, fundamental
rheology and baking characteristics of batters and breads from different gluten-
free flours treated with a microbial transglutaminase. Journal of Cereal Science,
48, 33–45.
selinus, r. (1971). The Traditional Foods of the Central Ethiopian Highlands.
Uppsala: Scandinavian Institute of African Studies.
seyfu, k. (1997). Tef. Eragrostis tef (Zucc.) Trotter. Promoting the Conservation and
Use of Underutilized and Neglected Crops. Rome: Institute of Plant Genetics and
Crop Plant Research; Gatersleben: International Plant Genetic Resources
Institute.
spaenij-dekking, l., kooy-winkelaar, y. and koning, f. (2005). The Ethiopian cereal
tef in celiac disease. New England Journal of Medicine, 353, 1748–1749.
steinkraus, k. h. (1986). Fermented foods, feeds, and beverages. Biotechnology
Advances, 4, 219–243.
stewart, r. b. and dagnachew, d. (1967). Index of Plant Diseases in Ethiopia, Experi-
ment Station Bulletin No. 30. Dire Dawa: Alemaya University.
tadesse, e. (1975). Tef (Eragrostis tef) cultivars: morphology and classification, Part
II, Agricultural Research Station Bulletin No. 66. Dire Dawa: Debre Zeit Agri-
cultural Research Station. Alemaya University of Agriculture.

© Woodhead Publishing Limited, 2013