Impact of different harvest times on fatty acid profile, sterol, tocopherol and bioactive properties of hazelnut oil

Abstract

This study was carried out to determine the effects of different harvest times of hazelnuts on their lipid profiles and bioactive compound accumulations. Tombul hazelnut cultivar was harvested at four different harvest stages, namely in PH (pre-harvest time), EH (early harvest time), NH (normal harvest time) and LH (late harvest time). According to the results of the study, oil accumulation continued up to NH but did not further increase into LH (from 49.58 to 58.54 mg/100 g). Oxidative stability indices changed positively due to decreased poly-unsaturated fatty acids (PUFA) from 9.87 to 7.70% in LH. The highest total sterol amount was reached in LH (122.32 mg/100 g). Although the change in the tocopherol content in the oil was irregular with the progression of the harvest time, its amount in the nuts increased continuously. Total carotenoid, phenolic, flavonoid, and antioxidant activity (DPPH and ABTS) peaked in EH and decreased to a minimum in LH.

Keywords

• Antoxidant activity
• Fatty acid profile
• Hazelnut oil
• Oxidative stability
• Sterol
• Tocopherol