ABSTRACT
Natural fats and oils extracted from plants and animals serve as a primary source of lipid in human diet. Lipids are an important nutrient for energy, essential fatty acids (linoleic, linolenic, and eicosanoic fatty acids), and fat-soluble vitamins. They also play a very important role in growth and development, disease prevention, and maintenance of good health. Primarily, the composition and combination of fatty acids in a particular fat or oil determines its physicochemical property and nutritional value. The nutritional quality of lipids is determined by 1) content of essential fatty acids, 2) ratio of unsaturated (monounsaturated and polyunsaturated) to saturated fatty acids, 3) presence or absence of medium-chain fatty acids, and 4) presence or absence of cholesterol. However, there is no single source of lipid that can meet all of these requirements. The conventional lipids derived from plants are normally rich in unsaturated long-chain fatty acids and animal lipids are high in saturated fatty acids. Fish oils, on the other hand, are known for their high content of docosahexaenoic (DHA) and eicosapentaenoic (EPA) acids. Further, the physical properties, such as melting behavior, physical state (solid, semisolid, and liquid) at ambient temperature, and stability, determine the functional and commercial value of lipids such as cocoa butter.
