Effect of drying methods on fatty acid profile and oil oxidation of hazelnut oil during storage

Abstract

This study’s objective was to assess the fatty acid composition and oil oxidation traits of hazelnuts that were dried with a drying machine (DM), on concrete ground (CG), and grass ground (GG) during 12-month storage (2014–2016) at 20–25 °C and 70–90% relative humidity. The result showed that monounsaturated was the major fatty acid groups (83.56–85.03%) in hazelnut, followed by polyunsaturated (9.36–11.17%) and saturated (5.61–6.60%) fatty acids. Furthermore, the minor fatty acid contents found were approximately 0.5% that of the total fatty acids. However, none of the following were found at detectable level: caproic acid (C6: 0), caprylic (C8: 0), capric (C10: 0), lauric (C12: 0), eicosadienoic (20: 2), erucic (22: 1), docosadienoic (22: 2) and lignoceric (C24: 0) acids. Consequently, the comparison showed that over 12-month storage, drying hazelnut using DM provides products with a higher oxidative stability than those using sun-dried methods (i.e., CG and GG). Therefore, DM seems to be suitable procedure for drying hazelnut.