In the broadest sense, a mixture of lipids—chiefly triglycerides (lipids containing three fatty acid molecules linked to a molecule of glycerol). More specifically, the term refers to a lipid mixture that is solid at room temperature (20şC); lipid mixtures that are liquid at room temperature are called oils. The higher the proportion of saturated fatty acids in a mixture, the harder the fat.
Boiling fats in strong alkali forms soaps (saponification). Fats are essential constituents of food for many animals, with a calorific value twice that of carbohydrates; however, eating too much fat, especially fat of animal origin, has been linked with heart disease in humans. In many animals and plants, excess carbohydrates and proteins are converted into fats for storage. Mammals and other vertebrates store fats in specialized connective tissues (adipose tissues), which not only act as energy reserves but also insulate the body and cushion its organs.
As a nutrient fat serves five purposes: it is a source of energy (9 kcal/g); makes the diet palatable; provides basic building blocks for cell structure; provides essential fatty acids (linoleic and linolenic); and acts as a carrier for fat-soluble vitamins (A, D, E, and K). Foods rich in fat are butter, lard, margarine, and cooking oils. Products high in monounsaturated or polyunsaturated fats are thought to be less likely to contribute to cardiovascular disease.
ETYM Old Eng. grese, grece, French graisse; akin to gras fat, greasy, from Late Lat. grassus thick, fat, gross, Latin crassus. Related to Crass.
A thick fatty oil (especially one used to lubricate machinery); SYN. lubricating oil.
ETYM French, bacon, pig's fat, Latin lardum, laridum.
Soft white semisolid fat obtained by rendering the fatty tissue of the hog.
Clarified edible pig fat. It is used in cooking and in the manufacture of margarine, soaps, and ointments.
ETYM Old Eng. taluh, talugh; akin to od. talgh, Dutch talk, German, Dan. and Swed. talg, Icel. tôlgr, tôlg, tôlk; and perhaps to Goth. tulgus firm.
Obtained from suet and used in making soap, candles and lubricants.