Hazelnuts analysis

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. 

Agricirltrrral shell samples (walnut, almond, hazelnut cotton cocoon, and sunflower shells) were subjected to supercritical water extraction for producing hydrogen-rich gas mixtrrres (Demirbas, 2004). Table 6.10 shows stractrrral analysis results of the shell samples. In a typical nm of this study, the autoclave was loaded with a 5.0 g... 

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. 

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). 

Parcerisa, J., Casals, I., Boatella, J., Codony, R., and Rafecas, M. 2000. Analysis of Olive and Hazelnut Oil Mixtures by High-Performance Liquid Chromatography — Atmospheric Pressure Chemical Ionisation Mass Spectrometry of Triacyglycerols and Gas-Liquid Chromatography of Non-Saponifiable Compounds (Tocopherols and Sterols). J. Chromatogr. A. 881 149-158. 

Glintert, M., Emberger, R., Hopp, R., Kopsel, M., Silberzahn, W., Werkhoff, R. (1991) Chirospe-cific analysis in flavour and essential oil chemistry. Rart A. EUbertone the character impact compound of hazelnuts. Z. Lebensm. Unters. Eorsch. 192. 108-110... 

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... 

Of the tree nuts, only the almond and hazelnut kits have been evaluated in independent studies. In December 2004 the Veratox Almond kit completed a full evaluation in seven laboratories that met the criteria for it to be added to Health Canada s Compendium of Food Allergen Methodologies (Health Canada, 2004). Although this evaluation does not confer endorsement of the method, the consistent approach adopted means that the methods can be used for enforcement in Canada should it be required. The study required 630 samples to be analyzed by the laboratories 10 replicates at each of three levels (0, 6.25, and 15.63 ppm) in cookies and in milk and plain chocolate. The kit produced satisfactory results for the matrices and at the levels tested. Analysis of plain chocolate produced the lowest recoveries, as expected, due to the presence of tannins and other phenolic compounds that interfere with the extraction of proteins. 

A recent analytical procedure by Flores et al. targeted the optimization of the interface performance in the online coupling of reversed phase liquid chromatography and gas chromatography (RPLC-GC) coupling by means of a horizontally positioned PTV (Programmed Temperature Vaporizer) injector. It improved the sensitivity achievable in the direct analysis of olive oil-mixtures with 5% or 12% of some virgin and refined hazelnut oils, respectively, based on the analysis of fil-bertone enantiomers within 30 min and without any kind of pretreatment. 

Flores, G., Castillo, M.L.R., Herraiz, M., and Blanch, G.R Study of the adulteration of olive oil with hazelnut oil by on-line coupled high performance liquid chromatographic and gas chromatographic analysis of filbertone. Food Chemistry, 97(4), 742-749. 2006. 

Alasalvar, C., Shahidi, R, and Cadwallader, K.R., Comparison of natural and roasted Turkish Tombul hazelnut (Corylus avellana L.) volatiles and flavor by DHA/GC/MS and descriptive sensory analysis, J. Agric. Food Chem., 51, 5067-5072, 2003. 

Alasalvar, C., Odabasi, A.Z., Demir, N., Balaban, M.O., Shahidi, E, and Cadwallader, K.R., Volatiles and flavor of five Turkish hazelnut varieties as evaluated by descriptive sensory analysis, electronic nose, and dynamic headspace analysis/gas chromatography-mass spectrometry, J. Food Sci., 69,... 

Ozay, G., Seyhan, F. Yilmaz, A. (2006) Sampling hazelnuts for aflatoxin uncertainty associated with sampling, sample preparation, and analysis. J. AOACInt. 89,1004-1011. 

C. Alasalvar, E. Pelvan, B. Btihar, F. Korel, H. Olmez, Flavour of natural and roasted Turkish hazelnut varieties (Corylus avellana L.) by descriptive sensory analysis, electronic nose and chemometrics. Int. J. Food Sci. Technol. 47, 122-131 (2012)... 

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