Refining olive oil

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. 

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). 

The main component of the tocopherol mixture is a-tocopherol which makes up 95% of the total. The other 5% of the mixture consists of (J>- and y-tocopherols. All tocopherols occur in the free (non-esterified) form. The vitamin E(mg) PUFA(g) ratio in olive oil is approximately 1.8. In countries with a high annual per capita consumption, a significant percentage of the daily requirement for vitamin E is covered by olive oil. Refined, bleached, and deodorised olive oils have markedly reduced tocopherol content because of losses during processing. 

Olive oil Olive Oil, Refined. See Olive (Olea europaea) oil... 

Trade Name Synonyms EmCon Olive [Fanning http //www.fanncorp.com], Fanoliv Oil [Fanning http //www.fanncorp.com], Lipovol O [Lipo http //www.lipochemicals.com], Nikkol Olive Oil [Nikko Chems. Co. Ltd http //www.nikkoi.co.jp/index.htmi], Olive Oil, Refined [Natural Oils Int l. http //www.naturaioiis.com, Tri-K Ind. http //www.tn-k. com]... 

Safflower (Carthamus tinctorius) oil Super Refined Safflower USP Tri-OI SAF 8001-25-0 Cropure Olive EmCon Olive Fanoliv Oil Lipovol O Nikkol Olive Oil Olive Oil, Refined Olive (Olea europaea) oil Phytol 0 Phytol O Pomace Pure/Riviera Olive Oil NF Super Refined Olive NF Tri-OI OLV 8001-26-1... 

Thiourea inclusion compounds have also found recent applications as diverse as the separation of liquid crystal isomers isolation of petroleum constituents and the recovery of squalene during olive oil refining to cite just a few examples. 

BondioU P, Mariani C, Lanzani A, FedeU E, Mossa A, Muller A. 1992. Lampante Olive Oil Refining with Supercritical Carbon Dioxide. J. Am. Oil Chem. Soc. 69(5) 477-480. 

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. 

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... 

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