Abstract: In this study, kernel oils from different hazelnut varieties, European hazel (Corylus avellana L.), Corylus heterophylla, and their hybrids Liaozhen No.3 and Dawei were comparatively analyzed for their physicochemical properties, fatty acid composition and antioxidant activity. Obvious differences in physicochemical properties of hazelnut kernel oil were observed among the different varieties, which ranged from 137.15 to 147.50 g I2/100 g in iodine value and from 144.99 to 159.03 mg KOH/g in saponification value. Acid and iodine values were lower in Corylus heterophylla kernel oil, whereas Corylus avellana L. kernel oil presented a higher acid value and kernel oil from both hybrids had a higher iodine value. In addition, there was a considerable difference in saponification value between both hybrids. Oleic acid (67.69%–82.26%) was the most abundant one in each hazelnut variety followed by linoleic acid (11.37%–14.24%). The contents of unsaturated and polyunsaturated fatty acids were 84.37%–94.31% and 11.84%–16.39%, respectively. In DPPH free radical scavenging assay, the IC50 values of kernel oils from these hazelnut varieties were between 23.63 mg/mL and 42.40 mg/mL and in decreasing order were Liaozhen No.3, Corylus heterophylla, Dawei and Corylus avellana L.. These results suggest that Corylus heterophylla and its hybrids with Corylus avellana L. are superior to Corylus avellana L. in terms of unsaturated fatty acid content and antioxidant activity.

Key words: hazelnut, oil, physicochemical properties, fatty acid, antioxidant activity