蒸汽爆破对沙棘籽粕多酚提取及生物活性的影响

Effect of Steam Explosion on Extraction and Bioactivity of Polyphenols from Seabuckthorn(Hippophae rhamnoides L.)Seed Meal

为提高沙棘籽粕利用率,研究蒸汽爆破(steam explosion,SE)压力和时间对多酚含量的影响,探究爆破前后多酚的抗氧化活性和α-葡萄糖苷酶抑制率,并通过高效液相色谱(high-performance liquid chromatography,HPLC)对爆破前后沙棘籽粕游离酚和结合酚进行成分分析。结果表明,当蒸汽爆破条件为2.0 MPa、90 s时,多酚和黄酮有最大提取率为7.62%和0.68%,较未爆破时分别提高了17.05%和25.93%;扫描电镜(scanning electron microscopy,SEM)分析表明,爆破后沙棘籽粕紧密结构被破坏,出现较多孔洞,比表面积增大;爆破后游离酚活性高于结合酚,其DPPH自由基和α-葡萄糖苷酶的半数清除率(IC50)分别为0.66 mg/mL和0.84 mg/mL,并与浓度存在较好的相关性;HPLC分析表明,爆破前后多酚组成较一致,但含量差异明显,爆破后游离酚提取物中芥子酸含量为未爆破组的1.3倍,结合酚提取物中儿茶素、7-羟基香豆素和阿福豆苷分别为未爆破组的1.7倍、8.5倍和3.2倍。综上,利用蒸汽爆破可以提高沙棘籽粕废料利用价值,改善多酚活性,为沙棘籽粕多酚进一步研究提供参考。

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 andα-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 andα-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.