Bioactive compounds of the different types of olive oil

In recent years, scientific evidence has shown a multitude of benefits attributed to the consumption of olive oil, the main source of fat in the "Mediterranean Diet", which is why it is becoming one of the first-choice elements in a healthy diet. The beneficial effects of olive oil are attributed to its components: oleic acid, the main monounsaturated fatty acid in the triacylglycerides of the olive (68-81,5%) and, therefore, in all the oils derived from it, and a series of compounds of different chemical nature, minority in terms of their concentration (1-2%) and that are distributed heterogeneously in different parts of the olive, and, consequently, in the different types of oils from the same.

These characteristic bioactive compounds are polyphenols, present mainly in the pulp, and triterpenic acids, present mainly in the skin and bone. Thus, not all olive oils are the same, and consequently, not all have the same beneficial properties for health. It is necessary to know the types of olive oil and the differences in their composition, to be able to substantiate the different effects that each of them can have on health.

Oils from olives

Virgin olive oil (AOV) is "the juice obtained by pressing the fruit of the olive tree, Olea europea L., in perfect ripeness conditions and from a healthy olive tree". To be classified as "extra" virgin olive oil (EVOO) it must be of a superior quality, which implies excellent physicochemical (acidity less than 1º) and sensory (qualified by letter panel) properties. Among the minority components present, polyphenols (hydroxytyrosol and tyrosol, and their derivatives oleuropein and oleocanthal, among others) stand out, as well as tocopherols and, in lower concentrations, triterpenic acids (0,05-3%). Its presence varies depending on the variety of the olive (Picual, Hojiblanca, Arbequina, etc.), the degree of ripeness of the fruit at the time of harvesting, and the characteristics of the soil, the climate, and the process used for the production. oil extraction. In addition to providing aroma, taste and color to the oil, these compounds are responsible for most of the biological activities and functional properties of EVOOs and EVOOs.

Refined olive oil is extracted with organic solvents from the solid residue from the AOV extraction, so the presence of minor bioactive components is practically nil.

Ordinary olive oil, marketed under the name "olive oil", is a mixture of AOV or EVOO and refined, and the content of minor components is considerably lower than that of AOV or EVOO, therefore its functional activity it is also considerably smaller.

Pomace oil is obtained with solvents from the pomace, a by-product of the olive that contains the remains of the skin, bone and pulp of the olive after the extraction of the AOV, which means that it contains few polyphenols from the pulp, but that is enriched in other components present in the skin and bone, mainly triterpenic acids.

These bioactive components provide specific organoleptic aroma and taste characteristics, and in turn beneficial properties. Olive pomace oil is also a mixture of pomace oil and EVOO or AOVE, containing in small quantities the minority components that the EVOO or AOV provide.

Beneficial effects of bioactive components

Traditionally, the beneficial effects of AOV and EVOO have been attributed to their high oleic acid content, which provides cell membranes with adequate fluidity to facilitate their functionality, without increasing their instability. However, nowadays it is known that olive oil is more than a monounsaturated fat, and that the minor components are the main responsible for its benefits.

It is very difficult to identify all the compounds (more than 230) present in the minority fraction of the oil, not only because of their low concentration and complex chemical nature, but also because many of them are eliminated during the processing and storage of the oil. Among the characteristic bioactive components of olives we find:

Polyphenols stand out for their antioxidant activity (they prevent the oxidation of LDL and other cellular components), anti-inflammatory activity, improve HDL concentrations and its functionality, reduce postprandial lipemia, protect endothelial function contributing to antihypertensive activity, modulate apoptosis, they have antiproliferative and antithrombotic effects, and decrease angiogenesis. These mechanisms are the basis of its protective activity against cardiovascular and neurodegenerative diseases, and some types of cancer.
Triterpenic acids, such as oleanolic and maslinic acids, and other triterpene derivatives, have demonstrated their antihypertensive capacity, and to restore disorders associated with cardiovascular risk factors, such as obesity, diabetes, and atherosclerosis, as well as antioxidant, anti-inflammatory, and antitumor.

Maria Dolores Mesa-Garcia She is Professor of Biochemistry and Molecular Biology at the University of Granada, member of the Department of Biochemistry and Molecular Biology II and of the "José Mataix Verdú" Institute of Nutrition and Food Technology (Biomedical Research Center) of the University of Granada. He is also a member of the Granada Biosanitary Research Institute (ibs.GRANADA) and head of the Granada node of the RICORS-SAMID network Primary care promotion of maternal, child and women's Health for prevention of adult chronic diseases (RD21/0012/0008) of the Carlos III Health Institute. Her main line of research is focused on the study of the effects of functional foods and ingredients on chronic oxidative and inflammatory-based pathologies, such as cardiovascular diseases and metabolic syndrome.