Fats constitute one of the three major classes of food products. The other two are proteins and carbohydrates. Fats are glyceryl esters of fatty acids.
Fats, as do carbohydrates, contain the elements carbon, oxygen, and hydrogen, but the proportion of oxygen in fats is less, and it can be said that fats are fuel foods of a more concentrated type than are the carbohydrates.
Dietary fats are a concentrated source of energy. Fats supply about 9 kcal/g, as compared with about 4 kcal/g from proteins and carbohydrates. An additional advantage of fat form viewpoint of energy availability is that it stores well in large amounts in adipose tissues.
Thus fat, considered to be a reserve form of fuel for the body, is an important source of calories.
Among functions of fats:
*Heat transfer – pan frying, deep frying
*Shortening power – biscuits, pastries, cakes, cookies
*Emulsions – Mayonnaise, salad dressings. Sauces, gravies, puddings, cream soups
*Varying melting points – candies
*Plasticity – confection, icings, pastries, other baked goods
*Flavor/mouthfeel – flavor
*Texture – creaminess, flakiness, tenderness
Paradoxically, this is not advantageous in affluent societies where the problem is not the availability of food for energy, but rather the health hazard of obesity.
The majority of added fats in the diet are invisible. They are the hidden fats of fried foods and baked goods, sauces and mixed dishes, and dips and spreads. Other invisible fats include the fats the marbling of meat and the fat ground into lunch meats and hamburger.
Fats may occur in foods as materials that are solid at room temperatures or as oils that are liquid at room temperatures. This physical property depends mainly on the fatty acids that they contain.
Solid fats contain comparatively small amounts of fatty acids with two or more groups of adjacent carbons that are not fully saturated with hydrogen.
Fats in foods
