What are fats

Fats consist of a group of compounds that are insoluble in water. Although the terms ‘fats’ or ‘oils’ are commonly used to refer to these compounds, they simply reflect differences in physical state.

At room temperature an ‘oil’ is a liquid fat and a ‘fat’ is a solid oil. All fats are composed of individual fatty acids and it is these which primarily determine the properties of the fat e.g. nutritional value and whether the compound is solid or liquid. A large proportion of fats in nature are present in the form of triglycerides, in which three individual fatty acids are attached to a molecule of glycerol (Figure 1).

Figure 1      Structure of a triglyceride