Fats and oils belong to the group of naturally occurring compounds called Lipids (Greek, lipid=fat). Lipids are those consituents of animals and plants which are soluble in organic solvents such as either, chloroform of animals and plants which are soluble in organic solvents such as ether, chloroform, carbon tetrachloride, benzene, hexane etc., but insoluble in water. The lipids which yields fatty acids and alcohols on hygrolysis with aqueous base (saponified) are refered to as Simple Lipids. These can be further divided into two classes:
- Fats and Oils which yields long-chain fatty acids glycerol upon hydrolysis;
- Waxes, which yields long chain alcohols upon hydrolysis;
Fats and Oils
Fats and oils are most important found in nature. They are one of the three major 'food factors' needed for human body, the other two being proteins and carbohydrates.
Fats and Oils widely distributed for human body, They provide concentrated reserve of energy in animal body for maintaining optimum body temperature. One gram of merabolised fat or oils yields 9 kcal, while the corresponding value for carbohydrates and protein are 4 kcal and 5-5 kcal respectively. Not only the edible fats and oils occupy a place of pride in human diet but they also find use as raw material for the manufacturer of soaps and synthetic detergents, plants and varishes, polishes, glycerol, lubricants, drying oils cosmetics, printing inks, linoleum oil cloth and pharmaceutical. At the reflects both their nutritional and industrial importance.
Natural Sources
Fats and oils come from a variety of sources - animals, plants and Marine organisms.
Animal Fats: are located particularly in adipose tissue cells. These are distended with oils droplets at body temperature but solidify death. Thus we have tallow from cattle, sheep and goats, and lard from hogs. In the human body about 12% of its total weight is fat. At least half of it forms a protective connecting tissue,bones and around nervous tissue, kidney, hearts and other organs.
Butter and ghee are special type of animal fats because they are made from milk 🥛.
Vegetable Oils: They are chiefly present in seeds and nuts of plants. They are stored in seeds to serve as nourishment for the germination of embryo. There are quite a few seeds and nuts which are rich in 'fat content'. Thus soya bean, groupnut, coconut and palm kernel; sesame seed and niger are all important sources of edible oils. Cotton seed, linseed, castor seed and mowrah give nonedible oils in various industries.
Marine Oils: These are obtained from water animals- sardines, hearings, sakmons whales, dolphins, seals, porpoises etc.
In India animal fats are not used as food because large section of the population is vegetarian. The traditional place of honour goes to ghee and butter-despite their having animal source- and vegetable oils particularly groundnut oil, coconut oil, rape or mustard oil, cotton seed oil, sesame oil etc.
