Regulations, tests and procedures

The law requires that certain parameters be met for classification of the various types of oil, including parameters:

  • Free acidity (in % of oleic acid)
  • Peroxide index (mEq O2/Kg of oil)
  • Organoleptic evaluation through panel tests

United States

Parameters and ratings established by the United States Standards for Grades of Olive Oil and Olive-Pomace Oil (75 FR 22363) for the categorisation of various types of olive oil.

Md -> median defect Mf -> fruity median

Category of
olive oil
Acidity
(%)
N° of peroxides
(MEQ.02/KG)
K232 K270 Organoleptic evaluation
(PANEL TEST)
Extra virgin olive oil ≤ 0,8 ≤ 20 ≤ 2.50 ≤ 0.22 Md = 0
Mf > 0
Virgin olive oil ≤ 2.0 ≤ 20 ≤ 2.60 ≤ 0.25 Md ≤ 2,5
Mf> 0
Lampante olive oil > 2,0 No limit No limit No limit Md > 2,5

European Union

Parameters and ratings established by European Union regulations (EEC Reg. 2568/91 and subsequent modifications) for the categorisation of various types of olive oil.

Md -> median defect Mf -> fruity median

Category of
olive oil
Acidity
(%)
N° of peroxides
(MEQ.02/KG)
K232 K270 Organoleptic evaluation
(PANEL TEST)
Extra virgin olive oil ≤ 0,8 ≤ 20 ≤ 2.50 ≤ 0.22 Md = 0
Mf > 0
Virgin olive oil ≤ 2.0 ≤ 20 ≤ 2.60 ≤ 0.25 Md ≤ 3,5
Mf> 0
Lampante olive oil > 2,0 No limit No limit No limit Md > 3,5

How can we establish if an oil is extra virgin or simply virgin?

Before reaching the dining table, every oil must pass a series of tests to certify its characteristics are extra virgin or virgin.

It is important to note that acidity does not refer to what we usually identify as “acid taste.” Rather, acidity refers to a chemical parameter that measures free fatty acids the oil contains, expressed as oleic acid. The level of acidity is a commodity index, but it has no bearing on the taste.

While an initial chemical and physical analysis requires particular ability and laboratory instrumentation, a sensory analysis consists in an overall evaluation of the oil via the senses, including smell and taste.

How does the tasting work?

Extra virgin olive oil is the only food that requires a method of sensory analysis that is regulated on a European Community level (Reg. 2568/91).  The United States also has regulatory requirements for olive oil under the Standards for Grades of Olive Oil and Olive-Pomace Oil (75 FR 22363).

The following is a portion of tasting procedures from above mentioned regulations:

After having measured out approximately 15 grams of oil (1/3 glass), the taster slightly tilts the glass, rotating it so that he can coat the inside of the glass as much as possible. Then he smells the sample through short inhalations of a few seconds in length.

After the olfactory test, the evaluation passes to the flavor, which is the combined sensation of smell, taste and texture.

Once this is completed, the taster takes a sip of oil of approximately 4-5 grams to permit the olive oil to progressively come into contact with all the taste buds within the mouth, beginning with the tip of the tongue, then the sides, and the back, finishing with the anterior and posterior pillars of the palate.

All of this is necessary as the four basic tastes – sweet, salty, sour and bitter – vary in intensity according to area.

In summary, in order to judge true extra virgin oil, four steps are required:

  1. A visual examination, defining color and clarity. This step is not required by official panel test rules from above mentioned regulations.
  2. An olfactory examination, defining intensity and persistence, and positive and negative attributes.
  3. A gustatory examination, defining intensity and persistence, and positive and negative attributes.
  4. A tactile examination, defining consistency.

It is worth remembering that each defect perceived in the oil can be attributed to an incorrect step along the production chain.

The criteria commonly applied for the designation of extra virgin olive oil are:

  • Chemical and physical parameters such as: level of acidity, indexes of oxidization, indexes of purity and genuineness, etc.
  • Sensory analysis (or panel test) of the organoleptic characteristics (smell, taste, consistency), describing positive and negative attributes.

The debate on sensorial analysis or panel tests

A sensorial analysis consists of an examination carried out by a panel of qualified experts.

Unfortunately, there have been many cases of non-homogeneous evaluation, which have led questioning the reliability of this type of testing because it is based on a high level of subjectivity. Too often, results varied between groups and sometimes within the same panel.

A study carried out in Spain in Autumn 2012 further confirmed the issue with taste panels yielding varying results. Approximately 200 samples of oil were analyzed in a dozen official laboratories recognized by the International Olive Council and the Spanish Ministry of Agriculture, Food and Environment. The research revealed that on average the panel’s results varied by 27% when testing the same samples of olive oil.

This data highlights the need for further review and standardization.

Thus, as a result certain producers felt there was a need to strengthen the process around panel tests to legitimize the taste testing processes for evaluating the criteria of objectiveness, repeatability and reproducibility.

In Italy, all the associations that are part of the supply chain (AIPO, ASSITOL, ASSOFRANTOI, CNO, Federolio, UNAPOL, UNAPROL and Unasco) have consequently signed an agreement to introduce a project that aims to shake up the entire sector of olive cultivation. Within the various points of the agreement, there is the common understanding to establish a working committee responsible for improving the practices of the panel tests.

To this end, we support ASSITOL’s (Italian Association of Oil Industry) proposal that was also presented to the anti-counterfeiting Committee of the Chamber of Deputies, which serves to guarantee blind testing both in the first analysis and in the counter-analysis (it is true that the tasters cannot see what they are tasting, but the head of the panel can, and this may condition the activity of the group).

Moreover, the blind tests would be followed by a final test based on chemical markers for the identification of organoleptic defects by using analytical instruments to verify the tasting results.

A series of scientific studies similar to this are currently under way with the goal of establishing standardized markers. The introduction of markers would provide additional security, allowing companies to operate with increased transparency and, more importantly, with increased trust.