Oil, hazelnut

The application of 13C NMR for the rapid analysis of the oil composition of oil seeds is well known [16], 13C NMR has recently been applied to the quantitative analysis of the most abundant fatty acids in olive oil [17]. The values obtained by this method differed by only up to 5% compared with GLC analysis. The quantitative analysis was applied to the olefmic region of the high resolution 13C NMR spectrum of virgin olive oil to detect adulteration by other oils which differed significantly in their fatty acid composition. The application of the methodology for the detection of adulteration of olive oil by hazelnut oil is more challenging as both oils have similar chemical profiles and further experiments are in progress. 

Use of cosolvent. Various cosolvents, such as acetone, ethanol, methanol, hexane, dichloromethane, and water, have been used for the removal of carotenoids using SC-CO2 extraction (Ollanketo and others 2001). All these cosolvents except water (only 2% of recovery) increased the carotenoid recovery. The use of vegetable oils such as hazelnut and canola oil as a cosolvent for the recovery of carotenoids from carrots and tomatoes have been reported (Sun and Temelli, 2006 Shi, 2001 Vasapollo and others 2004). For the extraction without cosolvent addition, the lycopene yield was below 10% for 2- to 5-hr extraction time, whereas in the presence of hazelnut oil, the lycopene yield increased to about 20% and 30% in 5 and 8 hr, respectively. The advantages of using vegetable oils as cosolvents are the higher extraction yield the elimination of organic solvent addition, which needs to be removed later and the enrichment of the oil with carotenoids that can be potentially used in a variety of product applications. 

Samples. Eleven hazelnut oils, 25 olive oils, and 7 other types of oil (canola, soybean, corn, sunflower, sesame, walnut, and peanut) were purchased from local grocery stores and Internet suppliers. For the adulteration studies, 10 olive oil and 10 hazelnut oil brands were randomly chosen from the samples purchased, and blends of olive oil... 

Correct Eleven hazelnut oils, 25 olive oils, and 7 other types of oil were purchased. (Adapted from Ozen and Mauer, 2002)... 

P4 The hrst part of this study involved structurally differentiating between hazelnut oil and other oils and then detecting adulterating oils in hazelnut oil. For this purpose, the spectra of pure hazelnut oil were compared with the spectra of seven other oil types, as shown in Figure 1. (Adapted from Ozen and Mauer, 2002)... 

Ozen, B. F Mauer, L. J. Detection of Hazelnut Oil Adulteration using FT-IR Spectroscopy. J. Agric. Food Chem. 2002,50, 3898-3901. 

Pfnuer, P., Matsui, T., Grosch, W., Guth, H., Hofmann, T., and Schieberle, P. 1999. Development of a stable isotope dilution assay for the quantification of 5-methyl-(E)-2-hepten-4-one Application to hazelnut oils and hazelnuts. J. Agric. Food Chem. 47 2044-2047. 

A difficult fraud determination is the addition of hazelnut oil to olive oil, and no official methods are described at present. In a relatively recent paper (Garcia-Gonzales et al, 2004), ANN applied to H and 13C NMR... 

Hazelnut oil Peach kernel oil Pumpkin seed oil Rice-bran oil... 

Blanch, G.P., Caja, M.M., Leon, M. and Herraiz, M. (2000) Determination of (E)-5-methylhept-2-en-4-one in deodorised hazelnut oil. Application to the detection of adulterated olive oils. J. Sci. Food Agric., 80, 140-144. 

Contini, M., de Santis, D. and Anelli, G. (1991) Distribution of fatty acids in glycerides and in free fatty acid fraction of hazelnut oil. Riv. Ital. Sost. Grasse, 68, 405-411. 

Gordon, M.H., Coveil, C. and Kirsch, N. (2001) Detection of pressed hazelnut oil in admixtures with virgin olive oil by analysis of polar components. J. Am. Oil Chem. Soc., 78, 621-624. 

Mariani, C., Bellan, G., Morchio, G. and Pellegrino, A. (1999) Free and esterified minor components of olive and hazelnut oils their potential utilisation in checking oil blend Riv. Ital. Sost. Grasse, 76,... 

The Padley and Timms (1980) method has been the subject of a collaborative trial which showed the method to be suitable for use by competent laboratories for the analysis of fats that did not contain added milk fat, hazelnut oil or the CBE Calvettta , which has a rather different triacylglycerol composition to other CBEs (FSA, 2001). 

Currently, work in the fats and oils sector is focusing on developing methods for the detection of fraudulent addition of hazelnut oil to olive oil. As mentioned earlier, this is currently a major issue of concern because there are no reliable methods for its detection. The chemical composition of hazelnut oil is very... 

Brereton, P. and Crews, C. (2001) Detection of Hazelnut Oil Addition to Extra Virgin Olive Oil. Final Report to the Food Standards Agency. Central Science Laboratory, York, UK. 

An amber-yellow coloured oil with a pleasant characteristic odour. Particularly suited to greasy complexions as it rapidly penetrates the skin, having an astringent and circulatory stimulating effect in addition to its nutritive properties. When diluted with other carriers like sunflower or grapeseed the blend may benefit conditions like acne. Cosmetically hazelnut oil is used in sun filter lotions and creams, soaps, shampoos and other hair products. Its main fatty acids are oleic (70-84%), linoleic (9-19%) and stearic (1-4%). It has been reported to cause immunological urticaria (a skin condition also known as hives) and in common with other nut oils there is a possibility of anaphylactic shock. 

Adulteration of fats and oils is another matter of concern, which might occur accidentally or deliberately. Rendering of pork fat and beef tallow in the same equipment without proper washing is an example of accidental and unintended con-tamination/adulturation. However, often cheaper oils have been sold in place of, or mixed with, more expressive oils. Thus, before to the recognition of health benefits of hazelnut oil, this oil was an adulterant in ohve oil (10). As mentioned earher, different oils have considerably different sterol compositions. Thus, sterols could be a means of identifying adulterants because often fatty acid compositions of the adulterant and the original oils are similar (11-13). 

The fatty acid composition of hazelnut oil is as follows 78-83% oleic acid, 9-10% linoleic acid, 4—5% palmitic acid, and 2-3% stearic acid as well as other minor fatty acids (Table 3) (1, 22). Parcerisa et al. (23) examined lipid class composition of hazelnut oil, showing that triacylglycerols constituted 98.4% of total lipids, glycolipids comprised 1.4% of total hpids, and trace amounts (<0.2%) of phosphatidylcholine and phosphatidylinositol were also present. Hazelnut oil contains 1.2-1.14 g/kg of phytosterols primarily in the form of p-sitosterol and is a very good source of a-tocopherol (382-472 mg/kg) (1, 22). The main odorant in... 

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