Regulation (EEC) N. 2568/91 of 11 July 1991 on the characteristics of olive oils is in force since 1991. It allows classifying olive oils according to certain characteristics. Currently, the classification of live oils provides different major categories including virgin olive oils. These are defined as oils obtained from the fruit solely by mechanical or other physical means under conditions that do not cause the deterioration of the oil. Such oils have not undergone any treatment other than washing, decantation, centrifugation or filtration. The oil most sought after by the consumer, and qualitatively superior, is the extra virgin olive oil. This is defined as virgin olive oil, which is free of acidity, expressed as oleic acid, for no more than 0.8 grams per 100 grams and its characteristics correspond to those fixed for this category.

Among these we find:

  • Peroxides: it indicates an alteration of oxidative type. The oxidative rancidity is performed by enzymes called lipoxidase and is favored by external activators such as light, heat and the presence of traces of metallic substances.
  • The oxidation is synonymous with aging and degradation: expressed in mill equivalents of active oxygen per kilogram of oil (meg O2/kg). The limit on the number of peroxide is 20, above which the oil is clear.
  • EEAG (ethyl esters of fatty acids) ≤ 30 mg / kg: increased levels of ethyl and methyl esters of fatty acids is observed as a result of fermentation and degradation.
  • Spectrophotometric constants: K232, K270 and DK are determined by the spectrometer in the lab by reading the absorption at 232 and 270 nanometers. The limits for an extra virgin olive oil are 2.5 for K232 and K270, and 0.2 to 0.01 for DK.
  • Sensory analysis: this method allows classifying oils according to the intensity of the defects perceived and the fruitiness by a panel of selected trained and monitored tasters. The oil is graded according to the median of defect and the median of fruitiness attributed by the panel. An extra virgin olive oil must have the median of the defects as 0 and the median for fruitiness greater than 0.

Failure to meet any one of the characteristics indicated above involves the oil to be graded as virgin oil or lampante olive oil when even a single parameter does not meet the requirements of the virgin olive oil.