采收时间及加工方式对青钱柳叶化学成分含量及抗氧化和降血糖活性的影响

Effects of harvest time and processing methods on chemical components and antioxidant and hypoglycemic activities of Cyclocarya paliurus leaves

目的比较不同采收时间、加工方式对青钱柳叶黄酮、三萜及多糖含量与体外抗氧化和降血糖活性的影响,为青钱柳的采收加工提供依据。方法采用回流法提取青钱柳黄酮、三萜及多糖,紫外分光光度法检测含量;以青钱柳45%乙醇提取液清除DPPH·、OH·、ABTS^(+)·能力以及对α-葡萄糖苷酶抑制能力为指标评价青钱柳体外抗氧化活性与降血糖能力。结果采收时间、叶片颜色以及加工方式不同,导致青钱柳黄酮、三萜及多糖含量存在明显差异但呈现一定的规律性变化,抗氧化及对α-葡萄糖苷酶抑制能力也产生差异。各样品黄酮含量在2.64%~6.79%之间,三萜含量在3.67%~8.92%之间,多糖含量在1.13%~4.86%之间;6月绿色叶阴干样品对α-葡萄糖苷酶抑制能力最强,7月绿色叶杀青样品抗氧化能力最强且具有较强抑制α-葡萄糖苷酶作用。结论综合分析,确定以6、7月份采摘绿色青钱柳叶并采用杀青方式处理为最佳。

Objective To compare the effects of different harvesting time and processing methods on the contents of flavonoids,triterpenoids and polysaccharides in Cyclocarya paliurus leaves,and their antioxidant and hypoglycemic activities in vitro,to provide basis for the harvesting and processing of Cyclocarya paliurus.Methods Flavonoids,triterpenoids and polysaccharides from Cyclocarya paliurus leaves were extracted by reflux extraction.The contents of flavonoids,triterpenoids and polysaccharides were detected by UV spectrophotometry.The antioxidant activity and hypoglycemic ability of Cyclocarya paliurus leaves were evaluated by scavenging DPPH·,OH·,ABTS+·and inhibiting a-glucosidase by 45%ethanol extract of Cyclocarya paliurus leaves.Results Different harvesting time,leave colors and processing methods led to significant differences in flavonoids,triterpenoids and polysaccharides contents,but showed certain regular changes,and the antioxidant and aglucosidase inhibitory capacity also had differences.The content of flavonoids ranged from 2.64%to 6.79%,triterpenoids from3.67%to 8.92%,and polysaccharides from 1.13%to 4.86%.The a-glucosidase inhibition ability of dried-in-the-shade samples in June was the strongest,the fixing samples in July showed the strongest antioxidant capacity and strong inhibition of aglucosidase.Conclusion According to the comprehensive analysis,the best way to pick green Cyclocarya paliurus leaves is in June and July and adopting dry-blanching method.