category: food/groceries: cooking fat

Oil and Fat

Fat, de.: Fett, fr.: graisse, it.: grasso, es.: grasa

Oil, de.: Öl, fr.: huile, it.: olio, es.: aceite

Fat and oil are found in many different forms. Sometimes as whipped cream on a dessert, other times in creamy sauces. Humans need fat. It belongs to the essential nutrients for us. Other basic nutrients are proteins, carbohydrates and vitamins. However only enjoyed in small amounts fat shows us its "good" side. Without fat humans could not survive. Our organism cannot produce unsaturated fatty acids. These have to be supplied by our diet. Deprivation of these fatty acids can lead to health problems. Fat soluble vitamins like vitamin A, D, E and K can for example not be used by our body without fat. 7 to 10 grams of fat cover the necessary daily amount of unsaturated fatty acids for adults. Linoleic acid belongs to the most important group of polyunsaturated omega-6 fatty acids. In animal fats only small amounts of linoleic acid are found.

Calorific value of fat and oil

Fat is contained in every living organism in different amounts. It serves mainly as an energy source. Of all nutrients fat has the highest calorific value. One gram of fat has a calorific value of 9,3 kilocalories (kcal) or 38,9 kilojoule (kJ) which is more than twice the amount of protein (16,8 kJ).

Processing

Vitamins and fatty acids in fat and oil are sensitive to heat, sunlight and oxygen. Only in fresh, raw fats are they unchanged. However raw, unprocessed fats cannot be sold – they would not be durable enough and the risk of spoiling because of contamination would be high. Depending on the fat or oil there are different processing methods to make them more durable. Fats are won, cleaned, refined or purified by using pressure, extraction, elution, centrifugation, and melting. Depending on kind they are mixed or hydrogenated.

Consistency of oil and fat

Whether an oil or fat is solid or liquid depends on the kind of fatty acids contained. The more saturated fats it contains, the more solid it is (for example suet or coconut oil). Fats with more unsaturated fatty acids are softer and tend to be liquid (for example soybean oil or olive oil).

Classification of oils and fats

Cooking fats are classified as animal and vegetable fats. For consumers however it makes more sense to classify fats as follows:

cooking oils,
solid vegetable fat,
butcher fat like suet or lard and
spreadable fats like butter and margarine