Extra virgin olive oil is a very precious food: it is important to carry out checks to make sure that the product you are bringing to the table is the right one. Often, the producers themselves think that, having used their own olives and traditional methods, the product is at its best. In reality, a large part in the quality of the final product is also played by the conservation of both the olives and the oil produced, and by the attention during production.
Just one small misstep is enough to damage the organoleptic characteristics, and consequently the quality of the final product.
In general, the quality of a product can have multiple facets, so it is advisable to establish in advance what is meant by "Quality".
In the case of extra virgin olive oil, we can distinguish the quality from both a chemical and organoleptic point of view.
The organoleptics of the oil takes into consideration the flavor and smell, which can be positive, such as fruity, bitter and spicy, or negative such as sludge, rancid, metallic.
As regards the chemical part, some parameters are considered which indicate a healthy quality of the oil, that is, they have a positive impact on the human body, and other parameters which represent a "chemical" quality, and indicate both the quality of the raw material from which was extracted, and the oxidation state in which it is found.
The chemical parameters that can provide us with this information are: Acidity, number of peroxides, ultraviolet spectrophotometric analysis, etc.
Acidity is the main quality indicator of the raw material (olives) and is formed following the degradation of the cellular structure of the fruit: this parameter, therefore, allows us to trace the state of degradation of the oil.
EEC Reg. 2568/91 and subsequent amendments indicates that for an oil to be considered Extra Virgin Olive Oil it must maintain a maximum acidity value of 0.8%.
Usually, however, a quality extra virgin olive oil has an acidity value in the range of 0.1-0.3%. Analyzing our oil the degree of acidity is equal to 0.21%, highlighting that it is a high quality product
It is important to point out that acidity cannot be perceived on an organoleptic level, this is because the molecules that compose it (Free Fatty Acids) are so small that they are unable to interact with the taste buds of the oral cavity.
The number of peroxides indicates the oxidation state of the product, causing its degradation and aging.
This value is expressed in milliequivalents of oxygen per kg of oil (mEq O2/kg) and the EEC Reg. 2568/91 e sm indicates a maximum value of 20 mEq O2/kg for virgin and extra virgin olive oil, beyond which the oil is classified as "Lampante". From the chemical analysis of the oil produced in our company, the number of peroxides is equal to 3.5 meq.
Ultraviolet Spectrophotometric Analysis allows you to determine which of the two oxidative phases the product is in.
EEC Reg. 2568/91 and subsequent amendments indicates limit values to be respected for K232, K270 and Delta-K.
These parameters indicate the absorption of ultraviolet light in the wavelengths of 232 and 270 nanometers (nm), which respectively indicate the more or less high presence of Hydroperoxides (Primary Oxidation) or Aldehydes and Ketones (Secondary Oxidation).
The other important function of this type of analysis is to provide information regarding product fraud and contamination.
In fact, the values of K270 and Delta-K are far higher in refined oils than in virgin oils.
The spectrophotometric test values obtained from the “D&C Olio D'oliva” oil are:
K232=1.72
K266=0.20
K270=0.18
K274=0.16
Delta K=0.003
In summary, from the chemical analyzes carried out at Finoliva Global Service, accredited by Accredia, it emerges that:
