Refining olive oil and

Olive oil is an oil that is a blend of refined olive oil and virgin olive oils, except for virgin lampante olive oil it has a free acidity, expressed as oleic acid, of not more than 1.5 g 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 . 

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. 

The designation olive oil has been expanded to olive oil composed of refined olive oil and virgin olive oil . This is much more meaningful and reflects more accurately exactly what this product is, i.e. a blend of refined olive oil and virgin olive oil. As a result of improvements in oil refining, it has also been possible to reduce the maximum acidity permitted for this grade of oil from 0.5 to 0.3 g per 100 g. 

Olive oil—composed of refined olive oils and virgin olive oils Olive oil obtained by blending refined olive oil and virgin olive oil, other than lampante oil, having a maximum free acidity, expressed as oleic acid, of 1.0g per 100g and the other other characteristics laid down for this category. 

D. Olive oil the oil consisting of a blend of refined olive oil and virgin olive oil in various proportions. 

Total Sterol Content. The gas liquid chromatographic method for sterol determination using an internal standard (cholestanol) is used to calculate the absolute (total) sterol content of an oil (68, 69). Gravimetric, enzymatic, colorimetric, and liquid chromatographic methods have also been reported (69). Limits (mg/100 g) are as follows (12) virgin olive oil, refined olive oil, and olive oil (mixture of refined and virgin) >100 crude olive-pomace oil >250 and refined ohve-pomace oil, olive oil and olive-pomace oil (mixture) >180. 

Differentiation Between Virgin and Refined Oiive Oil and Detection of Refined Olive Oil and Seed Oils in Virgin Olive Oil... 

Refined olive oil and mixtures have the following limits (12) ... 

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. 

OE031 Ghimenti, G., and G. Taponeco. Ter- OE041 penic dialcohols in olive oil and their modification during the course of refining. Riv Soc Ital Sci Aliment 1974 ... 

The PV is greatly reduced by the refining process used for most vegetable oils. Virgin olive oils are not exposed to such processes and the PVs permitted in these products are considerably higher. Extra-virgin olive oils are permitted PVs <20 meq/kg under international standards, whereas pure olive oils, which by definition are blends of virgin and refined olive oils, are required to have PVs <10 meq/kg. 

Fragaki, G., Spyros, A., Siragakis, G., Salivaras, E., and Dais, P. (2005). Detection of extra virgin olive oil adulteration with lampante olive oil and refined olive oil using nudear magnetic resonance spectroscopy and multivariate statistical analysis. J. Agric. Food Chem. 53, 2810-2816. 

Ntsorankoua, H., Artaud, J. and Gueree, M. (1994) Triterpene alcohols in virgin olive oil and refined olive pomace oil. Ann. Falsif. Exp. Chim Toxicol., 87, 91—107. 

These trans compounds have different physical properties than natural cis isomers and are readily separated with gas chromatography analysis. The detection of trans isomer fatty acids in an olive oil indicates addition of seed oils to olive oil, of refined olive oil to virgin olive oil and of esterified oil to residue olive oil and olive oil. 

Gas chromatography is the most accurate means of quantifying the trans isomers present in fatty acid mixtures. In the GC trace the trans peaks appear broader because they contain isomers whose complete resolution is difficult. Virgin olive oils may show, in the sum of the trans-oleic acid-isomers, a maximum value of 0.05% and in the sum of /ran.v-linoleic and linolenic acid the same maximum value of 0.05%. Lower grade olive oils and refined olive oils are allowed wider limits for fatty acid trans isomers (see Table 2.2). 

Lanzon, A., Albi, T., Cert, A. and Gracian, J. (1994) The hydrocarbon fraction of virgin olive oil and changes resulting from refining. J. Am. Oil Chem. Soc., 71, 285-291. 

In some cases where extreme refining conditions have been used, complete removal of the sterols, both free and esterified, may occur (Grob et al., 1994). By removing the sterols from an oil in this way, it is possible to prepare an adulterant that is undetectable by sterol analysis. As with adulteration of virgin olive oil with refined olive oil, this type of adulteration may be detected by analysis of sterol degradation products. 

Fig. 4.34. Typical response of a LuPc2 Langmuir-Blodgett film expressed as the fractional change in resistance (AR/R) x 100 towards (a) refined olive oil (b) lampante olive oil (c) extra virgin olive oil and (d) ordinary olive oil. Reproduced with permission from N. Gutierrez et al., Sensors and Actuators B 77,437, 2001.

B. Virgin olive oil not fit for human consumption, also designated as lampante virgin ohve oil virgin olive oil that has an organoleptic rating of less than 3.5 and/or a free acidity, expressed as oleic acid, of more than 3.3 g per 100 g. This class of olive oil is used to produce refined olive oil or is intended for technical (nonfood purposes). 

Extra virgin, fine, and semifine virgin olive oil Refined olive oil Olive oil... 

Tocopherol Content. Tocopherols can be determined by colorimetry or GLC (90), or by HPLC (91, 92). Added tocopherols are not permitted in virgin olive oils and crude olive-pomace oils (12). Added ot-tocopherol is allowed in refined olive oil, olive oil, refined olive-pomace oil, and olive-pomace oil to restore natural tocopherol lost during refining with a maximum level of 200 mg/kg of total ot-tocopherol in the final product (12). 

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