Classification of Turkish hazelnut oils based on their triacylglycerol structures by chemometric analysis

Abstract

Triacylglycerol structures of Turkish hazelnut oils were determined to make classification by chemometric analysis. During 2009 and 2010 crop seasons, 50 samples of 19 hazelnut cultivars (Fosa, Sivri, Mincane, KalA +/- nkara, Kara, YassA +/- badem, Tombul, Allahverdi, Kus, CakA +/- ldak, Uzunmusa, Kargalak, AcA +/-, Yuvarlakbadem, Kan, Cavcava, A degrees ncekara, Palaz and Bolu) were collected from Giresun, Trabzon, Ordu and Bolu provinces of Turkey. Hazelnut oils were obtained by solvent extraction, and samples were evaluated for their fatty acid, sn-2 fatty acid and triacylglycerol compositions. Results have shown that water and oil content of the hazelnuts were between 3.17-4.32 % and 55.01-64.85 %, respectively. Oleic acid is the major fatty acid in all samples ranged between 81.03 and 86.63 %. Higher percentages of oleic acid were determined at sn-2 position of triglycerides as between 86.57 and 91.45 %, followed by linoleic and palmitic acids. Main triacylglycerols of hazelnut oils were OOO, OOL, OOP, SOO and OLL. Triolein was the major one ranging between 57.86 and 68.99 %. A one-way analysis of variance revealed significant differences between variables in the cultivars. Principle component and hierarchical cluster analyses enabled the classification of varieties based on their triacylglycerol structure. Discriminant analysis separated the samples according to their geographical origin.