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Home arrow The World of Oil arrow Tasting Olive Oils


by GIULIO SCATOLINI, Unaprol's Head of Panel

"No idea can be formed if man does not
irst perceive something by his senses"

Sensory analysis, generally speaking, is the result of a complex dynamic interaction between different physiological, sociological, cultural and financial conditions. In fact, we all use it daily to appraise and select food, clothing, work tools and persons, using our human senses.

Specifically, sensory analysis applied to olive oils can be said to have begun late. In fact, studies of sensory perception have been carried out for years, especially for food products on the market of the English speaking world. These studies have shown that human sensory organs behave like real testing instruments, meaning that mathematical laws dictating responses to a particular stimulus and its intensity have been discovered; furthermore, it has been discovered that sensory organs are formed by cells specialized in recognizing the single kind of molecules they come in contact with. Therefore, tests were performed to see if sensory organs possessed one of the fundamental characteristics of testing instruments: the ability to repeat tests and obtain the same results.

When an instrument is used to measure something, the result must be the same each time the test is done and regardless of who operates the instrument. All of this must be verifiable both in recognizing the type of substance tested and to measure its concentration. Thus, it was discovered that even human sensory organs work very well as instruments to detect a specific scent. For example, everyone can recognize the scent of a rose, which obviously means that specialized cells to detect this scent are found in everyone. Instead, in what regards perception intensity, tests were performed to determine the so-called sensory thresholds, meaning the intensity levels that can be perceived by individuals. There were a few surprises here, because it was discovered that these sensory thresholds depend on the individuals; for example, some people are extremely sensitive to bitterness, while others aren't so sensitive. This presented a problem: one person could give an appraisal based on the perceived intensity of a stimulus, which would differ from that of others. This meant a single person, regardless of how experienced and talented, could not be used for appraising the organoleptic properties of food items.

However, statistic analysis regarding personal sensory thresholds discovered that groups of 8-10 people, chosen randomly from amongst a population, have an average group threshold that is repetitive, meaning it is equivalent to that of other groups of 8-10 people from the same population.

This means that groups of 8-10 individuals have an average group threshold that can be considered representative of the whole population's threshold and, therefore, any such group can be used as a measuring instrument to obtain valid results for the whole population.

When such a group is used as a tasting panel to appraise the organoleptic properties of an olive oil, the people chosen are asked to evaluate the presence and intensity of the usual sensory elements found in oil, which can be pleasant and/or unpleasant. The pleasant ones come from substances that are already naturally present in healthy, fresh fruit, in the membrane that surrounds the oil droplets found inside the pulp's cells. When olives are processed, in the crushing and especially in the kneading stages, all the natural substances found in the fruit are distributed among the oil and the vegetable water according to their distribution coefficient, which is greatly influenced by temperature. Therefore, carefully controlling and limiting temperatures during extraction results into a harmonious transition of natural substances into the oil, especially those responsible for its organoleptic properties, resulting into a better product.

The organoleptic properties also include unpleasant substances, which are still not a good thing even when barely perceptible. These substances do not usually originate in healthy, fresh fruit, but rather form after olive degradation due to fermentation processes or environmental pollution. Detecting pleasant and unpleasant sensations is the goal of an organoleptic appraisal.

As in all other human affairs, when a person expresses an opinion, all that the person is doing is weighing positive and negative models already imprinted in their memory; thus all the people who make up the tasting panel are trained to memorize positive and negative oil models. The positive model is used to memorize pleasant sensations that come from natural substances found in healthy, fresh fruit and that, on the whole, represent olive oil's fundamental property: its fruitiness. The negative model, instead, is used to memorize unpleasant sensations, known as organoleptic defects, which come from substances that are a result of the fruit's degradation processes.

Each taster is individually and autonomously assigned to a specially designed and equipped booth where the tasting takes place according to the instructions printed on a form coded by the EC in Reg. 796/2002, which displays both models: the negative model with all the most common organoleptic defects found in olive oil; and the positive model with the perception of presence and intensity of fruitiness and all its shades of bitterness and spiciness, which can make it more or less harmonious. The taster then writes down the intensity with which he/she perceived the oil's merits and potential defects on the form.

The "Head of the Panel" then reviews the appraisals made by the different tasters and, if the severe variation factor (error in the method) is less than 20%, he/she then declares the evaluation reliable and therefore the appraisal of the median of the positive (merits) and negative (defects) perceptions is the final result that constitutes an objective evaluation of the oil's organoleptic properties.

This test has been used to establish the evaluation intervals of the numeric median corresponding to the various oil categories foreseen in Community Law. Therefore, extra virgin oil must have a defects median equal to zero and a fruitiness median greater than zero.

Instead, when the defects median is between 0 and 3.5 and the fruitiness median is greater than 0, oil is classified as virgin.

When the defects median is greater than 3.5, the oil is "lampante", meaning non-edible, and it therefore needs to be refined.



Unaprol, Italy's largest olive growers' consortium, established the Panel in order to possess a reliable testing instrument, which is currently essential for all those who concerned with the promotion and quality of extra virgin olive oil.

The sensory analysis laboratory was set up after visiting and carefully inspecting similar facilities throughout the nation, so as to create the most complete and practical tasting room possible.

The objective was certainly accomplished, since all experts and heads of panels that have visited the facility have been favourably impressed by the technical solutions and the quality of the materials used.

In regards to the tasting panel presided over by me, it has been recognized by the Ministry of Agricultural, Food and Forestry Policies (D.D. 4 May 2007), and is made up of members of Unaprol's technical staff as well as a series of heads of the panels that are periodically involved, depending on the area of origin of the oils to be tasted.

The high number of available samples from a large number of varieties, both pure and blended, from the most important productive regions nationwide and abroad, constantly trains our panel in a way that few other panels worldwide can boast.

The result: an extremely reliable panel, which is readily available to appraise the complex and varied production of high quality Italian olive oil.