Effect of altitude on fatty acid composition in Turkish hazelnut (Coryllus avellana L.) varieties
The objective of this study was to evaluate the change of fatty acid composition in Delisava, Yomra, Sivri and Karayaglı Turkish hazelnut varieties with altitude. Fatty acid composition were determined by gas chromatography (GC) equiped with flame ionisation detector (FID) after obtained fatty acid methyl esters from crude oil. According to the obtained results, total unsaturated fatty acids (USFA) ranged between 90.71-91.69 as percent. Total USFA composition in Sivri and Karayaglı hazelnut varieties significantly increased with altitude (p≤0.05) and Delisava and Yomra hazelnut varieties increased but not significantly (p≥0.05). Oleic acid ranged from 75.39-82.33%, followed by linoleic acid ranging between 7.85-14.74% of total fatty acid. The remaining 6 unsaturated fatty acids contributed only ranged between 0.85-1.51%. Oleic acid concentration in Sivri, Yomra and Karayaglı varieties increased with altitude as statistical significant (p≤0.05). In Delisava variety, oleic acid content did not change with altitude (p≥0.05). Total saturated fatty acid (SFA) composition in all varieties decreased with altitude (p≤0.05) but the changes in Sivri variety did not significantly (p≥0.05). Palmitic acid and stearic acid were dominant saturated fatty acids (5.99-5.26 and 2.42-3.49%, respectively) in all samples.Tetradecanoic acid (C14:0), pentadecanoic acid (C15:0), heptadecanoic acid (C17:0) and eicosanoic acid (C20:0) concentration did not change with altitude in all varieties as statistical significant (p≥0.05). Stearic acid concentration in all varieties decreased with altitude as statistical significant (p≤0.05). Palmitic acid content in Delisava variety decreased with altitude (p≤0.05); however, haxadecanoic acid content in other varieties did not change with altitude statistically (p≥0.05).
Key words: Hazelnut, altitude, fatty acid, Coryllus avellana L., MUFA, PUFA.