Attributes of Fats

Classification of Fats

LIPIDS are the class of substances that include all fats and fat-like substances. Fats are solid or semi-solid and oils are liquid substances that solidify between -20°C and +40°C.

Fat-like substances, called LIPOIDS, are not fat themselves, but are contained in all natural fats.

Hydrogenation

Oil-containing seeds like peanut or coconut yield liquid oil. Through hydrogenation, the liquid oil becomes a solid fat.

Fat - A Multiple Talent

Fat is more than high-calorie food.
It has a high calorific value and can therefore be used:

• As fuel
• As lubricant, separating agent and adhesive
• For the production of ointments and soaps
• As additive for paint and lacquer

Boiling Point, Smoking Point, Decomposition Point

Fats can be heated above 100 °C and have a very high boiling point. Fats used for food preparation must not be heated above their smoking point, since otherwise toxic substances (acrolein) are built. Decomposition is accompanied by pungent smoke.

Natural fats can be heated to higher temperatures if:

• The amount of water is small.
• They contain only few other substances, i.e. are pure fat (refined).
• The amount of saturated fatty acids is high.

Solubility

Fats have a lower specific gravity than water and are not soluble in water. Therefore, blobs of fat float on soups and sauces. Fats are soluble in petrol, ether and benzene, though. Fats themselves are solvents for the vitamins A, D, E and K, which are soluble in fat.

"Rancidity"

Oxygen, light, heat and bacteria cause the decomposition of fats into their components: glycerine and fatty acids. The fats deteriorate and develop a rancid taste. Especially fats with unsaturated fatty acids (e.g. butter) become rancid. For that reason, they should always be stored in a cool and dark place. Adding vitamin E delays rancidity.

The Structure of Fats and the Role of the Different Fatty Acids

Saturated fatty acids are mainly found in animal fats. Unsaturated fatty acids have no direct impact on the cholesterol level.

Characteristics of fat

• Not soluble in water

• High calorific value

• 1g fat = 9 kilocalories

• The higher the amount of saturated fatty acids, the higher the melting