The main senses that take part in the sensory analysis of Virgin olive oil are the sense of smell and the sense of taste. Both senses are so related that if we loose the sense of smell, every food that we eat would taste insipid. The sense of smell has huge sensory capacity. One of the main features of the sense of smell is that acts to small stimuli. To perceive aromas our organism has also developed, from its embryonic stage, a series of structures that facilitate this action. While some of these structures also perform important tasks related to breathing, as a whole they activate the brain response to allow us to catch different aromas. In the case of the sense of taste, the chemical substance has to be in direct contact with taste receptors. Contrarily, through the sense of smell we can capture remote and low concentrations of molecules that react with the specialized organs.
Set of olfactory sensations characteristic of the oil which depends on the variety and comes from sound, fresh olives, either ripe or unripe. It is perceived directly and/or through the back of the nose.
Characteristic primary taste of oil obtained from green olives or olives turning colour. It is perceived in the circumvallate papillae on the “V” region of the tongue.
Biting tactile sensation characteristic of oils produced at the start of the crop year, primarily from olives that are still unripe. It can be perceived throughout the whole of the mouth cavity, particularly in the throat.
Characteristic flavour of oil obtained from olives piled or stored in such conditions as to have undergone an advanced stage of anaerobic fermentation, or of oil which has been left in contact with the sediment that settles in underground tanks and vats and which has also undergone a process of anaerobic fermentation.
Characteristic flavour of oils obtained from fruit in which large numbers of fungi and yeasts have developed as a result of its being stored in humid conditions for several days.
Characteristic flavour of certain oils reminiscent of wine or vinegar. This flavour is mainly due to a process of aerobic fermentation in the olives or in Acid-sour olive paste left on pressing mats which have not been properly cleaned and leads to the formation of acetic acid, ethyl acetate and ethanol.
Flavour that is reminiscent of metals. It is characteristic of oil which has been in prolonged contact with metallic surfaces during crushing, mixing, pressing or storage.
Flavour of oils which have undergone an intense process of oxidation.
Other negative attributes
Heated or burnt
Characteristic flavour of oils caused by excessive and/or prolonged heating during processing, particularly when the paste is thermally mixed, if this is done under unsuitable thermal conditions.
Characteristic flavour of certain oils produced from olives that have dried out.
Thick, pasty mouthfeel sensation produced by certain old oils.
Flavour of oil reminiscent of that of diesel oil, grease or mineral oil.
Flavour acquired by the oil as a result of prolonged contact with vegetable water which has undergone fermentation processes.
Flavour of oil extracted from olives which have been preserved in brine.
Characteristic flavour of oil obtained from olives pressed in new esparto mats. The flavour may differ depending on whether the mats are made of green esparto or dried esparto.
Flavour of oil obtained from olives which have been collected with earth or mud on them and not washed.
Flavour of oil obtained from olives which have been heavily attacked by the grubs of the olive fly (Bactrocera oleae).
Flavour produced when an oil is hermetically packed for too long, particularly in tin containers, and which is attributed to the formation of 2,6 nonadienal.
Characteristic flavour of oils extracted from olives which have been injured by frost while on the tree.
We have to fill a normalized cup with 15 ml of oil to start with. Cover it with a glass to avoid the responsible compounds of aroma volatilize. Keep the tasting Cup at 28 ° C so you can perceive better the volatiles responsible for the aroma.
Then we tilt the cup while turning it to wet the inner surface of the tasting glass.
First we do a brief olfaction to capture the volatiles with lower molecular weight so we get a first impression. Then we do a second olfaction, this time more intense, trying to appreciate the intensity and type of fruity, green or mature, or a defect, if any.
At the end, we place a small amount of oil in the mouth while aspire air to try to reach all areas of the oral cavity, where the different sensory notes are detected, so we can appreciate the intensity and kind of fruity.
Panel of tasters
The panel shall consist of a head of panel and a number of tasters between eight and twelve.
The head of the panel shall be a knowledgeable and experienced expert in types of olive oil and a solid training. It will be responsible for the Panel, its organisation and functioning and preparation, coding and presentation of the tasters, as well as the compilation of data and statistical treatment samples.
The head of the panel will select the tasters and supervise their training and performance to ensure a suitable level of competence.
The organoleptic checks of olive oil tasters must be selected and trained based on their ability to distinguish between similar samples according to the international olive oil Council for the selection, training and qualified Virgin olive oil tasters control Guide.
Panels shall undertake to participate in the organoleptic evaluations scheduled at national, community or international levels for the periodic inspection and the harmonization of the criteria of perception.
In addition, in the case of panels approved in accordance with the provisions of article 4, paragraph 1, of this regulation, these must annually submit information on the composition of the panel to the Member State concerned and indicate the number of evaluations conducted in authorized panel quality.
Sensory evaluation and classification procedure
Use of the profile sheet by tasters
Each taster on the panel shall smell and then taste 1/ the oil under consideration. They shall then enter the intensity with which they perceive each of the negative and positive attributes on the 10-cm scale shown in the profile sheet provided.
Should the tasters perceive any negative attributes not listed before, they shall record them under the “others” heading, using the term or terms that most accurately describes the attributes.
They may refrain from tasting an oil when they notice any extremely intense negative attribute by direct olfactory means, in which case they shall record this exceptional circumstance in the profile sheet.
Use of the data by the panel leaders
The panel leader shall collect the profile sheets completed by each taster and shall review the intensities assigned to the different attributes. Should they find any anomaly, they shall invite the taster to revise his or her profile sheet and, if necessary, to repeat the test.
The panel leader shall enter the assessment data of each panel member in a computer program like that appended to this method with a view to statistically calculating the results of the analysis, based on the calculation of their median. See sections 10.4 and Annex 1 of this method. The data for a given sample shall be entered with the aid of a matrix comprising 9 columns representing the 9 sensory attributes and n lines representing the n panel members used.
When a defect is perceived and entered under the “others” heading by at least 50% of the panel, the panel leader shall calculate the median of the defect and shall arrive at the corresponding classification.
Use of the tasting by the taster tab
There is a model of tasting should use the tasters tab. Each of the members of the panel tasters should smell and then taste the oil subjected to assessment.
Then, must be entered on the scales of 10 cm tasting which will be made available the intensity with which perceives each negative attributes and positive (1) tab. In case of perception of the green or mature nature of the fruity attribute, the taster will mark the box on the tab of tasting.
Where negative attributes not listed in the tab tasting should be collected, shall be entered in the section “Other”, using the terms describing them more accurately among those defined.
Classification of oils
Oil falls into the categories listed below, depending on the median of defects and median fruity attribute. Defects median refers to the median of the defect perceived with greater intensity. The median of defects and median fruity attribute are expressed with a single number decimal and the solid coefficient of variation that defines value must be less than or equal to 20 %.
Oil classification is done by comparing the value of defects and the attribute frutado(fruity) with reference intervals following median (median). These ranges limits have been established taking into account the error of the method, so they are considered absolute. Computer programs allow a classification visual in a box of statistical data or graphically.
Extra virgin olive oil: the median of defects is equal to 0 and the “fruity” attribute greater than 0.
Virgin olive oil: the median of defects is greater than 0 and less than or equal to 3.5 and the “fruity” attribute greater than 0.
Lampante olive oil: the median of defects is greater than 3.5, or defects median is less than or equal to 3.5 and the “fruity” attribute is equal to 0.
Quality criteria applicable to the oil olive Regulation (EC) No. 640/2008
Classification of oils
Extra virgin olive oil: The median of defects is equal to 0 and the “fruity” attribute greater than 0.
Virgin olive oil: The median of defects is greater than 0 and less than or equal to 3.5 and the “fruity” attribute greater than 0.
Lampante olive oil: The median of defects is greater than 3.5, or defects median is less than or equal to 3.5 and the “fruity” attribute is equal to 0.