Comparative analysis of roasting conditions on the lipid composition, oxidative stability and healthy effects of organic versus conventional hazelnuts

This study was conducted to comparatively investigate the sensitivity of oil components of Giresun Quality Tombul hazelnuts grown with organic and conventional methods to heat treatment. For this purpose, natural hazelnuts were roasted under 6 different conditions (130, 145, 160 °C and 15, 30 min) and changes in moisture, oil, fatty acids, sterol, tocopherol compositions, carotenoid amounts, oxidative and health indices were determined. According to the study results, significant differences were detected among natural hazelnuts. It was observed that total sterol contents of organic hazelnuts were high (1224.28, 988.70 mg/kg) and tocopherol (74.85, 68.21 mg/100 g) contents were low. While palmitic acid amounts were high in conventional samples, no significant differences were observed in other fatty acids. In addition to the effect of separation of the skin by roasting, a decrease in β-sitosterol, α and γ-tocopherol, carotenoid amounts was recorded due to the effect of heat, and no significant change was detected in fatty acids except for the decrease in linoleic acid. No significant difference was observed between the heat treatment sensitivities of organic and conventional hazelnuts in terms of the parameters examined. As a result, it can be suggested that roasting process can be applied under the same conditions.