LIPID EXPERIMENT SBK 3013 Principle in Biochemistry Lab Practice | 2023
OBJECTIVES To detect the presence of lipid in daily food which is Pretz, KitKat, Oreo and kuih siput. To determine the percentage of lipid in daily food. To determine the type of fat in daily food. Upon completion of this experiment, we manage to: 1. 2. 3.
Lipids are a group of macromolecules that are soluble in organic solvents but insoluble in water. The word lipid actually origin from the Greek word lipos, which meaning “fat” or “lard”. Triglycerides, TAG and cholesterol are examples of lipids. Lipids can be stored by the body asnd serve as a fuel supply and essential component of cell structure. Lipids include substances including fatty acids, neutral fats, waxes, and steroids like cortisone. Compound lipids, or lipids complexed with various chemical substances, include things like lipoproteins, glycolipids, and phospholipids. Typically, lipid content in human daily food can be extracted by using a nonpolar solvent such as acetone or chloroform. The reaction of acetone with lipid will produces a white precipitate. This precipitate is a form of soap, which is made up of fatty acids and glycerol. The reaction is exothermic which it releases heat thus a slight warming sensation can be feel when acetone mix with the food sample. INTRODUCTION
01 02 The food sample was crushed finely using mortar and pestle and weighted about 1 g for the test. A clean test tube was labelled and weighted for this sample. The mass of the test tube was recorded and labelled. The sample of crushed food sample was added into the labeled test tube and weigh again. The value was recorded. About 5 mL of acetone was added to the test tube. The addition is being done in fume hood with precaution step is taken. METHODOLOGY 03 The food sample was swirled gently to make sure it soaked in the acetone for 5 minutes and allowing the fat to be extracted into the solvent. Centrifuged the mixture. Petri dishes is weighted and labelled. 04 The acetone was carefully pipetted into a clean labeled petri dish. All of the solid particles were made sure to remain in the beaker. Another 5 mL sample of acetone was added to the test tube. 05 06 Swirled it again for 5 minutes and decant the acetone to the petri dish. This step was repeated 3 times. The test tube was weighted and recorded with the remaining solids particles. This is the mass of the food sample without the fat. The petri dish was allowed to evaporate in the fume hood for about 30 minutes or until acetone is evaporated. The Petri dish was weighted again.
RESULT
Pretz KitKat OBSERVATION Oreo Kuih Siput
The extraction process is start with increasing the surface area of the food sample by grinding it to small pieces. Acetone is then is used to extract lipid from the food because acetone is a non – polar solvent. This non polar solvent can extract lipids from food by dissolving the lipids in the solvent. Lipids are hydrophobic which means they do not dissolve in water while non-polar solvents are hydrophobic thus it can dissolve all the lipids contain in the food. DISCUSSION Based on the observation onto the petri dish shows that the food that contain saturated fat will leave white precipitate and small white grain while the food with unsaturated fat will leave clear and oily precipitate when the acetone is fully evaporated. This phenomenon occurs because saturated fats are insoluble in non – polar solvent like acetone and they will precipitate out of solution when the acetone is evaporated. This is because saturated fats have single bonds in their chemical structure which make them more soluble in polar solvents like water. When the acetone evaporates, the saturated fats will be left behind as a white precipitate and small white grains. The food with unsaturated fat will leave clear and oily precipitate when the acetone is fully evaporated due to unsaturated fats have double bonds in their chemical structure which make them more soluble in non-polar solvents like acetone. When the acetone evaporates, the unsaturated fats will be left behind as a clear and oily precipitate.
Based on the table, it is shown that KitKat contain the highest fat saturation with 81.73% fat successfully extracted from 1.04 g of KitKat. One of the main reasons is there are 70% chocolate contain in 45g of KitKat. Chocolate contains oleic acid which is a monounsaturated fat. On the other hand, Pretz snack has the lowest fat saturation with only 8% fat successfully being extracted from 1g of Pretz. Pretz contains low saturation of fat but the fat’s type is saturated. This characteristic is given by the small amount of palm kernel oil that contain in it. Palm kernel oil is a saturated fat with high in lauric acid which is a type of saturated fat. Oreo and kuih siput shows a significant amount of fat in it with both of them contain 0.63 g and 0.61 g of fat in 0.98 and 1.02 g food sample respectively. This fat is contributed by canola oil that contain in both of it. Canola oil is a type of vegetable oil that is high in monounsaturated fat and also contain linoleic acid (omega-6 fatty acid) and alpha-linolenic acid (ALA, an omega-3 fatty acid) which are good for heart health. The lipid experiment is significant in our PrBL research because it identifies foods with the highest levels of saturated fat. It also reveals the types of fat present in our daily meals, which is important for determining which foods provide us with the most energy for our daily activities. This knowledge allows us to comprehend the lipolysis process, which occurs in our bodies during fasting and is also important for maintaining human energy production.
CONCLUSION In the nutshell, this lipid experiment manages to determine the fat content and saturation levels of various foods. Canola oil is a healthy fat that can be found in many foods, including Oreo and kuih siput. Palm kernel oil is a saturated fat that should be consumed in moderation. Saturated fat is not necessarily bad but it is important to consume it in moderation. Unsaturated fat is a healthy fat that can help to reduce the risk of heart disease. It is important to eat a balanced diet that includes a variety of healthy fats. This findings from the experiment are significant for PrBL research because they can be used to identify foods with high levels of saturated fat and to determine the types of fat present in our daily meals. This information can be used to make informed decisions about our diet and to improve our overall health.
REFERENCE 01 02 03 Banach, Maciej & Shekoohi, Niloofar & Mikhailidis, Dimitri & Lip, Gregory & Hernandez, Adrian & Mazidi, Mohsen & Group, Lipid & (ILEP), International. (2022). Relationship between Low-Density Lipoprotein Cholesterol, Lipid Lowering Agents and the Risk of Stroke: A meta-analysis of Observational studies (n=355,591) and Randomized Controlled Trials (n=165,988).. Archives of Medical Science. 18. 912-929. 10.5114/aoms/145970. 1Kotb-El-Sayed, Mohamed_kotb. (2020). Lipid Chemistry. 10.13140/RG.2.2.24865.84324. Higgs, Dave & Dong, Faye. (2000). Lipids and fatty acids.
APPENDICES
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