Olive oil categories

Olive oil classification has a history reaching back to ancient times. In fact the Romans were already well aware that the stage of maturity of the olives, whether they were taken directly from the tree, or picked up damaged (or not) from the ground, was sufficient to determine a different grading of the oil obtained (Cucurachi, 1989). Olive oil classification in Roman times was as follows  

Oleum ex albis ulivis top oil obtained from olives harvested just as the fruit is changing colour, from a deep green to green-yellowish, to dark violet and, finally, to black. 

Oleum viride, strictivum oil obtained from olives changing colour when odoriferous substances were added the oil was defined oleum ad unguenta and used as ointment. 

Oleum maturum oil obtained from mature olives picked from the tree. 

Oleum caducum romanicum or comune oil fromhealthy olives collected from the ground. 

The following definitions were taken from a primer on the naming of olive oil (Anon, 1991). 

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Table 2.3 presents a summary of the Annexes to EEC regulation 2568/91 and successive additions and amendments. Additional information has been inserted into the original summary format with indications of the purpose and scope of the content of each Annex. Annex I is a table gathering all the characteristic qualitative and quantitative data of the nine olive oil categories. 

Table 2.6 Median values of defects and fruity aroma, and their corresponding robust coefficients of variation, in relation to virgin olive oil categories...

Median of defects Robust coefficient of variation % Median of fruity aroma Robust coefficient of variation % Olive oil category... 

Table 8.2 Physicochemical criteria for distinguishing olive oil categories Purpose of test Parameter...

Lampante virgin olive oil category. Virgin olive oil having a free acidity, expressed as oleic acid, of more than 2.0g per 100g and the other characteristics laid down for this category. 

Because of its high nutritional value and the beneficial effects that some of its compounds exert, the price of VOO is relatively higher if we compare it with other edible oils. This fact could explain why so many adulterations have been found for VOO this matrix is susceptible to adulteration with cheaper olive oil categories (olive oil pomace, refined olive oil) and/or other edible oils. Com, cottonseed, canola, palm, peanut, soybean, and sunflower oils have been detected in adnlterated VOOs. 

Extra virgin olive oil (EVOO) belongs to the superior olive oil category and it is solely obtained from fruit of olive tree, Olea Europera, by mechanical means. 

Single-dose oral LD o values in rats, guinea pigs, rabbits, and mice were determined by Rowe et al. (1952) in a gavage study using 1,2-dibromoethane in olive oil. All reliable LDso values (lethal dose, 50% kill) for each species for the acute-duration category are recorded in Table 2-2 and plotted in Figure 2-2. 

The category correlations can be cancelled only when all the objects of the training set are in the same category, and the method is used as a class modelling technique. However, the bayesian analysis in ARTHUR-BACLASS has b n compared with the usual BA in classification problems about winra and olive oils and about the same classification and prediction abilities were observe for both methods. 

By EP, Forma and Tiscomia were able to detect two categories within the Ligurian olive oils (East and West Liguria oils) and also two categories within the Sardinian olive oils (coast and inner Sardinia oils). In both cases, the detected categories were interpreted as connected to well-recognized climatic differences. 

Virgin olive oil with the qualifier fine, a term that can be used at the production and wholesale stages, is a virgin olive oil that has a free acidity, expressed as oleic acid, of not more than 2g per 100 g and characteristics corresponding to those fixed for this category in Annex I to EC regulation 2568/91 and amendments. The oil is fit for consumption as is . 

Misbranding. Olive oil is unique in that it is the oil from one fruit marketed in nine different categories. Seed oils, instead, are almost all oils refined from a single seed species or a mixture of different seeds. Thus, on considering fraud and adulteration practices, it is advisable in the olive oil field to avoid misunderstanding by using the following words in accordance with their clearly strict definition ... 

Measurements of the first three categories of virgin olive oil must give a A K value not higher than 0.01 for refined olive oil and olive oil the limits are set at 0.16 and 0.13 values, respectively, whilst for oils of types 8 and 9 A K should not exceed the values 0.25 and 0.20, respectively. 

Long chain aliphatic esters, commonly called waxes, are components of epicuticular waxes of the olive fruits (Bianchi and Vlahov, 1994). Whilst in virgin olive oils the wax concentration is negligible, in olive-residue oil the wax content is considerable. Thus, the presence of long chain esters in olive oil is evidence of the presence of solvent extracted olive oil, also commonly called sansa olive oil. The detection and quantification of waxes in olive oil is an official method. As shown in Table 2.2, virgin olive oils fit for consumption must contain less than 250 mg/kg of waxes the limits are 350 mg/kg for categories 4,5 and 6, whilst for olive-residue oil the amount is expected to be over 350 mg/kg. 

This method has the main aim of detecting attributes and defects, and measuring their intensity, for the classification of the various categories of virgin olive oils (Angerosa, 2001). The sensory attributes perceived by the consumer arise from the stimulation of gustatory and olfactory receptors from a large number of volatile and some non-volatile compounds such as simple and combined phenols. The intensity of each sensation is related to the concentration of chemical compounds identified in the volatile fraction of the oil. 

The unpleasant odours of virgin olive oils of poorer categories derive from saturated and monounsaturated aldehydes (C5-C9), some dienals, C5... 

Table 2.5 Scores (overall grading) for each category of virgin olive oil...

Only these categories of olive oil may be sold at retail level. 

The new definitions and categories of olive oil, which are listed in Table 8.3, come into effect on 1 November 2003, with the exception of that for crude olive-pomace oil , which is effective from 1 November 2001. This allows producers time to adjust to the new system. 

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