The saponifiable fraction represents more than 98% of the composition of virgin olive oil. It is made up of all the fatty acids, whether they are combined to form triglycerides and diglycerides or are present as free fatty acids.
What we commonly refer to as fats are these fatty acids. They are classified according to their degree of saturation as saturated, monounsaturated, or polyunsaturated fatty acids, as shown below.
Classification of fatty acids according to their degree of saturation:
Fatty Acids:
Saturated: predominant in animal fats.
Unsaturated: predominant in vegetable fats.
Monounsaturated
Polyunsaturated
The physical, chemical, and nutritional characteristics of olive oil depend on the proportions of the different fatty acids it contains, since most vegetable oils contain the same fatty acids but in different amounts. For example, the chart below compares the fatty acid composition of several vegetable oils. This is known as the fatty acid profile.
Fatty Acid Profile of Some Vegetable Oils
Palmítico (ES) Palmitic (EN)
Esteárico (ES) Stearic (EN)
Oleico (ES) Oleic (EN)
Linoléico (ES) Linoleic (EN)
Linolénico (ES) Linolenic (EN)
Oliva (ES) Olive (EN), Girasol (ES) Sunflower (EN), Soja (ES) Soybean (EN), Cacahuete (ES) Peanut (EN), Palma (ES) Palm (EN)
Palmitic and stearic acids are saturated fatty acids, oleic acid is a monounsaturated fatty acid, and linoleic and linolenic acids are polyunsaturated fatty acids.
Most vegetable oils are rich in unsaturated fatty acids, with a few exceptions such as palm and coconut oils. Olive oil is characterized by its particularly high oleic acid content, which is present in higher concentrations than in most other vegetable oils.