不同干燥方法对生姜叶活性成分和抗氧化活性的影响

为研究不同干燥方法对生姜叶活性成分和抗氧化能力的影响,以黄酮、多酚、精油含量及精油组分为活性成分指标,以DPPH·、ABTS+·及·OH清除率为抗氧化能力指标,对比阴干、晒干、烘干、冷冻干燥及真空干燥5种干燥方法对生姜叶的影响。结果表明,与新鲜生姜叶相比,经过不同干燥处理后生姜叶的活性成分含量及抗氧化能力均有所下降。其中,冷冻干燥处理后的生姜叶黄酮、多酚及精油含量均是最高,分别为21.62 mg/g、1.56 mg/g和1.91%;对DPPH·、ABTS+·和·OH的清除化能力最高,分别为70.42%、79.65%和63.41%。其次分别为烘干、真空干燥、阴干及晒干。通过GC-MS分析,新鲜及5种干燥方法得到的生姜叶精油共鉴定出33种组分,其主要组分为α-柏木烯、乙酸异龙脑酯、(Z)-3,7-二甲基-2,6-辛二烯醛及甲基庚烯酮,主要分为7大类,分别为萜烯类、醇类、醛类、酚类、酸类、酮类及酯类。综合比较,冷冻干燥对生姜叶中的活性成分及抗氧化能力保留效果最好。

Effects of Different Drying Methods on Active Components and Antioxidant Activities of Ginger Leaves

The purpose of this paper was to study the effects of different drying methods on the active components and antioxidant activity of ginger leaves. The contents of flavonoids,polyphenols,essential oil and essential oil components were taken as the active ingredient indicators. The free radical scavenging ability of DPPH·,ABTS+· and ·OH were taken as the antioxidant capacity indexes. The effect of freeze drying,oven drying,vacuum drying,shade drying and sun drying on ginger leaves were compared. The results showed that the contents of flavonoids,total polyphenols and essential oils decreased after drying treatment compared to fresh sample. The highest contents of flavonoids,polyphenols and essential oils of ginger leaves were obtained by freeze drying,with the values of 21.62 mg/g,1.56 mg/g and 1.91%,respectively. Meanwhile,the free radical scavenging ability of DPPH·,ABTS+· and ·OH were the highest with the values of 70.42%,79.65% and 63.41%,respectively. Followed by oven drying,vacuum drying,shade drying and sun drying. More than thirty components were identified in the essential oils of fresh and dried ginger leaves by GC-MS analysis. The main components were α-cedarene,isobornyl acetate,(Z) -3,7-dimethyl-2,6-octadienal and methylheptenone. All those volatiles components were clustered into the following families,which were mainly classified into six categories:Terpenes,alcohols,aldehydes,phenols,acids and ketones. In conclusion,freeze drying had the best effect on the retention of active ingredients and antioxidant capacity in ginger leaves.