Fats and oils together are called lipids. Lipids are macronutrients which supply energy and they are more energy dense than carbohydrates and proteins. Apart from being fuel for the body, they perform several other functions in the body. This is their nutritive value.
They also have several roles to play in food preparation and production. Fats and oils have many functions to perform in cooking and baking. Here are some of the functions, fats are responsible for in specific products (1,2).
Medium of cooking
Oil or fat is a very efficient medium for cooking, they transfer heat well. It is used for shallow frying, deep fat frying, stir-frying, sautéing or any other type frying. Oil transfers heat efficiently to the centre of the food.
Fats add flavour to foods such as cookies, cakes, breads. Fats and oils have the capacity to absorb flavour and retain them. Oils can be infused with flavours from herbs and spices.
When the dough is made for baking biscuits or similar products fat separates gluten and starch layers. The fat melts while baking because of the heat and forms small air pockets. This results in flakiness in the biscuit which is very desirable.
Fats help in giving the characteristic golden-brown colour to products after frying or baking making the product appealing to the eye.
Fat helps in holding moisture in a product and increases the products shelf life. It prevents the product from drying and keeps the product moist and soft.
When sugar is creamed in cake or mousse mixture air gets trapped in. A stable foam is made by air bubbles that are trapped in the fat-sugar mixture. This helps the final product to be light and fluffy.
When fat is applied to the surface of products it gives a glossy appearance to the food, It gives a shiny and glossy appearance to the food products which makes them look very appetizing. It is because of the fats the gravies, sauces and vegetable preparations look so tempting!
Fats are made up of fatty acids that have different melting points. Some fatty acids melt at a lower temperature than others, that means the fats melt over a range of temperature and not at one particular temperature. This property of fats is called plasticity. Because of plasticity fats can be spread, manipulated and shaped. Because of plasticity, spreads and cheese can be made which can be spread as soon as they are taken out of the refrigerator.
Fat/oil and water mix is called an emulsion. Fat is an important component of an emulsion. Salad dressings, mayonnaise are emulsions.
While making a dough fat helps in lubrication and helps forming a network with gluten. Because of the fat, the dough is easier to mix and also handle. Trays are greased with fat so that products set in them can be easily removed,
It is a property that makes a person feel full. A product that contains fat gives the feeling of satisfaction and satiety.