不同干燥方式对牛蒡片多酚含量及抗氧化能力的影响

Effect of different drying methods on the polyphenols and antioxidant activities of burdock roots slices

本文研究热风干燥(Hot air drying,AD)、真空微波干燥(Vacuum microwave drying,VMD)、真空冷冻干燥(Vacuum freeze drying,VFD)、热风联合真空微波干燥(Hot air combined vacuum microwave drying,AD&VMD)、真空冷冻联合真空微波干燥(Freezing combined vacuum microwave drying,VFD&VMD)5种干燥方式对干制牛蒡片干燥时间、能耗、总酚含量、多酚组分及抗氧化能力的影响。结果表明:VFD和AD干燥牛蒡片所需时间和能耗明显高于其他干燥方式,相比于单一干燥方式,联合干燥方式更利于单咖啡酰基奎宁酸的保留,其中VFD&VMD干燥所得牛蒡片中5-咖啡奎宁酸和绿原酸含量最高,VFD干燥更利于双咖啡酰基奎宁酸的保留。抗氧化能力方面,VFD干燥所得牛蒡片的清除DPPH+·、ABTS+·和铁还原能力均最强,VFD&VMD干燥所得牛蒡片抗氧化能力仅次于VFD干燥所得样品,显著高于AD、VMD、AD&VMD干燥所得样品。

Effects of five drying methods including hot air drying( AD),vacuum microwave drying( VMD),vacuum freeze drying( VFD),hot air combined vacuum microwave drying( AD&VMD) and freezing combined vacuum microwave drying( VFD&VMD) on drying time,energy consumption,polyphenols content,phenolic compounds and antioxidant activities of burdock roots slices were analyzed. The results showed that VFD and AD dried products had the longer drying time and the higher energy consumption. The combination drying methods were more benefit for caffeoylquinic acid retention compared with the unity drying methods. Specially,VFD&VMD dried products had the highest content of 5-caffeoylquinic acid and chlorogenic acid,VFD dried products had the highest content of dicaffeoylquinic acid. For antioxidant activities,VFD dried products exhibited the strongest DPPH+·and ABTS+·scavenging ability,reducing power,followed by VFD&VMD,AD,VMD and AD&VMD.