Hazelnut seed oils

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

Matsui, T, Guth, H., Grosch, W. (1998) A comparative study of potent odorants in peanut, hazelnut, and pumpkin seed oils on the basis of aroma extract dilution analysis (AEDA) and gas chromatography-olfactometry of headspace samples (GCOH). Fett/I.ipid 100. 51-56... 

Group 3 A group of high-oleic acid, low-linoleic acid oils, such as olive oil from the pericarp of olive fruit. Seed oils, such as almond oil, hazelnut oil, or avocado oil, also belong to this group (Table 11.5). 

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. 

Oleosins are hydrophobic plant proteins found only in association with small storage oil drops. These oil bodies are discrete spherical organelles, mainly composed of triacylglycerols and are surrounded by a phospholipids/oleosin annulus. Several oleosins were lately described, confirming that all of them comprise three distinct domains a conserved hydrophobic domain of about 70 amino acid residues being particularly rich in aliphatic amino acids flanked by an N- and a C-terminal domain, which are more hydrophilic with less conserved amino acid sequences. Allergenic oleosins were identified in sesame (Ses i 4 and Ses i 5), nuts (peanut and hazelnut oleosins), legumes, and seeds (Capuano et al. 2007, Leduc et al. 2006). 

There are a number of minor oils, all of high value, most of which are marketed mainly either for medical purposes or for their flavour. Olive, evening primrose, borage, fish oils and cocoa butter are described elsewhere. Others include hazelnut, walnut, macadamia, almond, apricot, pumpkin, poppy-seed and rice bran oils. The process of testing for authenticity of these oils should be approached in the same way as for the bulk oils above, i.e. fatty acid profile, sterols, tocopherols and triglyceride composition. However, there is little generally available published material on the ranges of values to be expected... 

These are largely stored in the seeds of vegetables. Olive, corn, cotton, sunflower, soybean, sesame, peanut, hazelnut, dates, almonds and coconuts are the main sources of vegetable oils. 

Ebrahem, K.S., Richardson, D.G., Tetley, R.M., and Mehlenbacher, S.A., Oil content, fatty acid composition, and vitamin E concentration of 17 hazelnut varieties, compared to other types of nuts and oil seeds, Acta Hortic., 351, 685-692, 1994. 

That tocopherols are apparently nature s choice of antioxidant is demonstrated in Fig. 4, which is similar to a correlation observed by Hove and Harris (1951). Here the total tocopherol content of oils from babasu (1), beechnut (2), carrot (3), castor bean (4), cacao (5, 6), coconut (7, 8), corn (9, 10), cottonseed (11-13), hazelnut (I4, 15), linseed (16), oat germ (17), okra seed (18, 19), olive (20-25), palm (26-28), peanut (29-33), pecan (34, 35), poppyseed (36), rapeseed (37), rice bran (38), safflower (39), sesame (40, 4I), soybean (42-44), sunflower (45), and wheat germ (46-50), as reported by Lange (1950), have been plotted against their total linoleic plus linolenic acid content as reported by Hilditch (1956). The linoleic, plus linolenic acid content of oils from the same species varies, sometimes threefold. It is unfortunate that the content of tocopherol, linoleic acid, and linolenic acid have seldom been determined on the same sample. If Fig. 4 could have been prepared from such data, the correlation would probably be even more dramatic. 

The best food sources of vitamin E are vegetable oils, green leafy vegetables, whole grains, seeds and nuts. Almonds and hazelnuts contain 8.S-9.5 a-tocopherol equivalents per 40g serving, for an impressive 100% of the FDA s proposed reference daily intake (formerly US RDA). 

These can be, for example, special gourmet oils (almond, apricot, avocado, grape seed, hazelnut, and walnut) or oils used for pharmaceutical and cosmetic applications (corn germ, wheat germ, evening primrose, and borage). If the deoiled residual can also be used for food or cosmetic applications, the economy of the process increases substantially. 

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