Abstract:This study aimed to explore the influence of steam explosion（SE）pressure and time on yield of polyphenols from seabuckthorn（Hippophae rhamnoides L.）seed meal，which is expected to improve the utilization rate of the seed meal.Specifically，the antioxidant activity and α-glucosidase-inhibiting rate of the polyphenols before and after SE were studied，and high-performance liquid chromatography （HPLC）was used to analyze the composition of free phenols and bound phenols in the seed meal before and after SE.The results showed that after pretreatment of the seabuckthorn seed meal by SE at 2.0 MPa for 90 s，the maximum yield of polyphenols and flavonoids was 7.62% and 0.68% ，respectively，17.05% and 25.93% higher than that without the SE.Scanning electron microscopy（SEM）indicated that the tight structure of seabuckthorn seed meal was destroyed by SE，with more holes and the specific surface area increased.After SE，the activity of free phenols was higher than that of the bound phenols，and the half-maximal inhibitory concentration（IC50）of the free phenolsagainst DPPH and α-glucosidase was 0.66 mg/mL and 0.84 mg/mL，separately，showing concentration dependence.HPLC analysis showed that the polyphenol composition was consistent before and after SE，but the content was significantly different.Content of erucic acid in the free phenol extract was 1.3 times of that in the group without SE，and the content of catechin，7-hydroxycoumarin，and afzelinin the bound phenol extract was 1.7，8.5 and 3.2 times of that in the group without SE，respectively.In conclusion，SE can improve the value of seabuckthorn seed meal and enhance the activity of polyphenols，providing a reference for further research on polyphenols in seabuckthorn seed meal.