Lipids are a diverse group of naturally occurring molecules that are insoluble in water but soluble in organic solvents such as chloroform, ether, and benzene. They are essential components of the human diet due to their role in providing energy, supporting cell structure, and acting as carriers for fat-soluble vitamins such as A, D, E, and K. Chemically, lipids include triglycerides, phospholipids, sterols, and waxes, each performing unique functions in food and metabolism. Triglycerides, also known as triacylglycerols, are the most common form of lipids found in foods. They consist of one molecule of glycerol esterified with three fatty acids, which can be saturated, monounsaturated, or polyunsaturated. Saturated fatty acids lack double bonds, making them solid at room temperature, commonly found in animal fats like butter, ghee, and lard. Monounsaturated and polyunsaturated fatty acids contain one or more double bonds, respectively, and are usually liquid at room temperature, found in plant oils such as olive oil, sunflower oil, and soybean oil. Phospholipids are another significant class of lipids, consisting of two fatty acids, a glycerol backbone, and a phosphate group linked to a polar head group such as choline, ethanolamine, or serine. These molecules are amphipathic, meaning they have both hydrophilic and hydrophobic regions, allowing them to form cell membranes and act as emulsifiers in food products. Lecithin, commonly found in egg yolk, soybeans, and some meats, is an example of a phospholipid widely used in processed foods to stabilize emulsions like mayonnaise and salad dressings. Sterols, particularly cholesterol, are lipids with a complex ring structure that play a crucial role in maintaining membrane fluidity and serving as precursors for steroid hormones and bile acids. Plant sterols (phytosterols) are structurally similar to cholesterol and are found in vegetable oils, nuts, seeds, and legumes. Waxes are esters of long-chain fatty acids and alcohols, usually forming protective