Abstract: Pumpkin seeds from eight regions of China were selected as raw materials to prepare pumpkin seed oil using a twin-screw press. The basic physical and chemical properties and oxidation stability of different pumpkin seed oils were analyzed. The results showed that pumpkin seed oil mainly contained four fatty acids (palmitic acid, stearic acid, oleic acid and linoleic acid) with unsaturated fatty acids accounting for 80.565%–84.964% of total fatty acids. Pumpkin seed oils were rich in bioactive substances, such as total phenols (167.21–204.50 mg/kg), total sterols (1 204.38–1 604.51 mg/kg), α-tocopherol (25.7–58.7 mg/kg), γ-tocopherol (1 839.8–2 728.3 mg/kg) and δ-tocopherol (248.8–518.7 mg/kg). The results of Pearson’s bivariate correlation analysis showed that total phenol had a significant correlation with the free radical-scavenging capacity of polar components (P < 0.05). Lipid concomitants such as α-tocopherol made some contributions to the antioxidant ability of pumpkin seed oil. The results of principal component analysis (PCA) and cluster analysis (CA) showed that the functional components of pumpkin seed oils from different production areas were similar, which fell into two distinct clusters according to different contents of functional components. The pumpkin seed oil from Baiyin City, Gansu province gained the highest comprehensive score. The results of this study are meaningful for guiding the development and utilization of pumpkin seed resources.

Key words: pumpkin seed oil; fatty acid composition; lipid concomitants; oxidation stability; cluster analysis