Olive refined

SPE Polar compounds Olive, refined Qassification HPSEC —... 

Virgin olive oil contains considerable amounts of simple phenols that have a great effect on the stability/sensory and nutritional characteristics of the product. Some of the most representative are hydroxytyrosol (3,4-dihydroxyphenylethanol) and tyrosol (4-hydroxyphenylethanol) however, phenolic compounds are removed when the oil is refined (Tovar and others 2001). The phenolic content of virgin olive oil is influenced by the variety, location, degree of ripeness, and type of oil extraction procedure used, and that is why hydroxytyrosol can be considered as an indicator of maturation for olives (Esti and others 1998). Hydroxytyrosol concentrations are correlated with the stability of the oil, whereas those of tyrosol are not (Visioli and Galli 1998). 

Refined olive oil, including olive pomace oil E 307 a-tocopherol 200 mg F1... 

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. 

The IUPAC Commission on Oils, Fats and Derivatives undertook the development of a method and collaborative study for the determination of triglycerides in vegetable oils by liquid chromatography. Three collaborative studies were conducted from 1985 to 1987. Refinements were made in the method after the first collaborative study, and the second and third collaborative studies demonstrated that the method produces acceptable results. Materials studied were soybean oil, almond oil, sunflower oil, olive oil, rapeseed oil, and blends of palm and sunflower oils and almond and sunflower oils. Six test samples were analyzed by 18 laboratories from 11 countries in the second study 4 test samples were analyzed by 16 laboratories from 12 countries in the third study. The method for the determination of triglycerides (by partition numbers) in vegetable oils by liquid chromatography was the first action adopted by AOAC INTERNATIONAL as an IUPAC-AOC-AOAC method (103). 

Fig. 4 LC-GC-FID chromatograms for typical olive oils. The nearly complete absence of wax esters (esters 40-esters 46) and very low concentrations of steryl esters indicate a high-quality extra virgin oil. The concentration of free stigmasterol is low. C24-26-OH, fatty alcohols. In lampante oils, more wax esters and steryl esters are found. The concentration of stigmasterol increases more than campesterol if the oil was prepared from olives of low quality. Run at the same sensitivity, chromatograms of solvent-extracted oils are completely overloaded. The refined extraction oil was diluted 1 5 before running the chromatogram shown. Wax ester and steryl ester concentrations are very high. (From Ref. 34, p. 626.)...

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. 

In the following Dp-values calculated with the refined Eq. (15-3) and partition coefficients KpF assumed to equal 1 are used for estimating worst case migration rates for additives from polyolefins with Eq. (7-51). These estimated values are compared with experimentally obtained migration values carried out under well defined conditions for several additives from HDPE and different PP-types (Table 15-3a) into olive oil (O Brian et al., 1999 and 2000). The results are summarized in Table 15-3b. 

Three other GC analyses now used in authentication, largely for olive and other oils which should not be refined or solvent extracted, are the determination of waxes, aliphatic alcohols, triterpene alcohols (uvaol and erythrodiol), and stigmastadiene and other sterol-dehydration products (EEC, 1991). These analyses are used at present not to detect adulteration with other oils, but with solvent-extracted or refined oils. However, it is possible that, with solvent-extracted oils, wax, aliphatic alcohol and terpene alcohol compositions, could prove useful in differentiating or detecting different oils. 

With non-refined oils it is sometimes possible to extract intact DNA from them, apply PCR amplification, and then examine the product by gel electrophoresis. If any GM component is present, this would then be detectable. However, oils that are sold non-refined are not generally the oils that are being produced in GM forms. It is possible that in future there may GM olive, hazelnut, walnut or other non-refined oils, and it is likely that these could be tested in this way. One other oil product that can be tested is lecithin. Where there has been severe heat damage, it is not always possible to extract suitable DNA from the product, but, with samples that have been only mildly treated, it is often possible to achieve accurate results by PCR. Each case has to be evaluated separately depending on the condition of the sample, and the quality of the methods used. 

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. 

Both the press and centrifuge solid residues, called the pomace, can be extracted still further by solvent extraction. The oil thus obtained can, after refining, be included among edible-grade olive oils. 

Refined olive oil is an olive oil obtained from virgin olive oils using refining methods this oil has a free acidity, expressed as oleic acid of not more than 0.5 g per 100 g and characteristics corresponding to those fixed for this category in Annex I to EC regulation 2568/91 and amendments. 

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 ... 

Annex XIII Proof that refining has taken place Neutralization and decoloration of olive oil in the laboratory To prepare the oil sample for additional analysis, e.g. ultraviolet... 

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. 

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