Investigating the fatty acid composition of hazelnuts produced at the Black Sea region

This study was conducted to find out whether the fatty acid composition of the round type hazelnuts (Corylus avellana L.) commercially produced in Turkey varies between the Eastern, Central and Western Black Sea Regions. A total of 87 samples were collected including 46 in 2015 and 41 in 2016 and fatty acid composition was analyzed using gas chromatography (GC). Oleic acid (C18:1, 82.77%) was found to be the predominant fatty acid in hazelnut oil, which was followed by linoleic acid (C18:2, 8.46%), palmitic acid (C16:0, 5.39%), and stearic acid (C18:0, 2.53%), respectively. The statistical analysis was carried out using analysis of variance (ANOVA: the general linear model and Tukey's multiple comparison test) and linear discriminant analysis (LDA) to determine the effect of the regions on the fatty acid composition. The analysis results showed that the mean values of palmitoleic (C16:1), oleic, linoleic, linolenic (C18:3) and arachidic acids (C20:0) significantly differed between the regions in 2015 and mean values of palmitic, palmitoleic, stearic, oleic, linolenic, linoleic, eicosenoic, arashidic acids significantly differed between the regions in 2016 (P˂0,05). The highest monounsaturated fatty acid (MUFA) content was found to be in the Western Black Sea region (83.52%), while the lowest MUFA content was in the Eastern Black Sea region (81.84%) in 2015, highest MUFA content was in the Central Black Sea region (84.29%) and the lowest in the Western Black Sea region (83.07%) in 2016. The results of the LDA showed a success rate of 100% for the 2015 data and the most important discriminant independent variables were C16:0, C18:2, C18:3, C20:0, saturated fatty acids (SFA), and MUFA. The results of the LDA showed a success rate of 92.7% for the 2016 data and the most important discriminant independent variables were C16:0, C16:1, C18:3, and MUFA. According to the results of this study, the fatty acid composition of the hazelnut significantly different between the regions and it is foreseen that fatty acid composition should thus be one of the parameters used in the determination geographical origin of hazelnuts. Keywords: Hazelnut (Corylus avellana L.), Black Sea Region, fatty acid composition, Statistical Analysis, Linolenic Acid, MUFA