The olive oil consists of a saponifiable fraction (fatty acid triglycerides) and a non-saponifiable fraction (secondary components). The saponifiable fraction corresponds to 99% of the oil. The fatty acids found in the triglyceride composition of olive oil vary according to the variety, and partly depend on the region from which it comes. The limits set by the International Olive Oil Council for the composition of triglycerides in fatty acids are as follows: palmitic acid 7.5-20%, palmitoleic acid 0.3-3.5%, stearic acid 0.5-5%, oleic acid 55-83%, linoleic acid 3.5-21%, linolenic acid 0-1.5%.
According to Greek and International Legislation, olive oil is divided according to its characteristics and production method into:
✓ Extra-virgin olive oil
✓ Virgin olive oil
✓ Lampante virgin olive oil
✓ Refined olive oil
✓ Olive oil
✓ Crude Kernel Oil
✓ Refined Kernel Oil
✓ Biological olive oil
The factors that can affect, degrade or alter olive oil are either natural (glass fragments, pieces of plastic and metal, hair, dust, soil, impurities) or chemical (pesticide residues, volatile halogenated solvents, heavy metals, polycyclic aromatic hydrocarbons -PAHs, environmental pollutants which are mainly dioxins, polychlorinated biphenyls (PCBs), aromatic hydrocarbons, etc.
To enable the separation between the different types of oil, the physicochemical characteristics (acidity, number of peroxides, absorption coefficients K 270/K 232/ΔK) and other control parameters (fatty acid composition, trans fats, sterols, metals, aromatics) have been determined hydrocarbons) of each oil, as well as the organoleptic characteristics of the virgin oils, in such a way as to ensure the authenticity and quality of the products in question.
The kernel oils are oils obtained from the processing of olive kernels and are divided into 3 categories:
✓ Crude kernel oil.
✓ Refined kernel oil, with a maximum free acidity of 0.3 %, obtained by refining crude kernel oil.
✓ Kernel oil or oil from olive kernels, with a maximum free acidity of 1.0% and which is a mixture of refined kernel oil and virgin olive oil.
Seed oils are the oils obtained from seeds, fruits or other parts of plants, except the olive. Seed oils are cottonseed oil, corn oil, soybean oil, sesame oil, sunflower oil, peanut oil, rapeseed oil, palm oil, etc.
Physico-chemical analyzes of oils (olive oil, kernel oil, seed oil, etc.) are carried out in the laboratory to check their quality and authenticity.
Indicative list of analyzes for olive oil as well as for other fats and oils: