Olive oil and quality

Olive oil quality is more than just chemistry. The organoleptic characteristics of oils are also important. You can tell by the taste!
Quality assessment of olive oil requires two types of analysis. Physico-chemical analysis, to ascertain the genuineness of the oil starting out from the composition (glycerides, fatty acids, sterols, polyphenols…). The free acidity percentage value is likewise assessed as the key parameter for classifying olive oils (as virgin olive oil, refined olive oil and or olive oil). The other type of analysis that is essential, if we are to understand whether a given olive oil is a high quality product or not, is termed sensory analysis. Sensory analysis entails an assessment of the organoleptic characteristics of the oil (i.e. the characteristics that our senses perceive: color (vision), fragrance (sense of smell) and flavor (taste)).
Chemical analysis measures free acidity levels and the other physical parameters of olive oil, while sensory analysis focusses on its visual, olfactory and gustatory characteristics.

Sample analysis

Quality assessment of oils is not conducted on the entire quantity of the oil obtained during a given season. Instead, samples are taken sporadically from each product batch. These samples are subjected to meticulous physico-chemical and sensory analysis. Only then can it be decided to which class (as defined by EU regulations) the product will belong.

Tasting is more than just… tasting

While sensory analysis consists in tasting samples of the olive oil, these operations vary, as do the tasters themselves! There are in fact two types of sensory analysis: one is commercial in its approach, and the other legal. The analysts differ accordingly − as do their methods and their aims.

Commercial sensory analysis

Commercial sensory analysis is conducted by the producer of the olive oil, and by the buyer and end consumer. Analysis consists in ascertaining whether the oil is “acceptable”. The first thing the producer of the olive oil does after pressing is to sample some olive oil to carefully check its color, smell and flavor. Only if you have practical knowledge of this field can you can pick up on the nuances of the aroma of the various oils and how they vary from year to year. That requires years and years of hands-on experience. Likewise, olive oil purchasers who want to sell the oil on must check to make sure the sample meets their marketing needs. And − if you’ve purchased some olive oil or have received it as a present − aren’t you going to look at it, smell it and taste it to see if you like it? As you would with wine?

Legal sensory analysis

Legal sensory analysis is conducted by a panel of professional tasters, under a panel supervisor. The panel examines the olive oil sample in order to establish the goods class to which it belongs. 8-12 tasters are required for this operation. Selection of these tasters is conducted by the panel supervisor in accordance with an official method and following adequate training. This supervisor is a key player and, obviously, he/she is an olive oil expert. The test takes place in tasting cubicles. Each taster is provided with an olive oil sample and a form that he/she shall fill in with indications as to the product’s merits and demerits.

The following classification applies, as per current regulations (Reg. (EU) 2095/2016):

EXTRA VIRGIN OLIVE OIL: Median of defect (Md) = 0 and Fruity median (Mf) >0
VIRGIN OLIVE OIL: Median of defect (Md) ≤ 3.5 and Fruity median (Mf) >0
LAMPANTE OLIVE OIL: Median of defect (Md) > 3.5 or Median of defect (Md) ≤ 3.5 and Fruity median (Mf) = 0

Median of defect is understood as the median of defect most distinctly or markedly perceived.