紫玉兰花干燥方法对其活性成分和抗氧化性的影响

Effects of Drying Methods on Chemical Composition and Antioxidant Activity of the Flowers of Magnolia liliflora

以紫玉兰(Magnolia liliflora Desr)花为材料,采用晒干、阴干、热风干燥、微波干燥等不同的干燥方法进行处理,探索其对紫玉兰花黄酮、多酚含量及抗氧化性的影响。结果表明:不同干燥方法处理紫玉兰花,干燥速度快慢顺序为:微波干燥>热风干燥>晒干>阴干。阴干、900 W微波干燥和50℃热风干燥样品的黄酮、多酚含量及抗氧化性较高,晒干处理对多酚、黄酮的分解损失最大,抗氧化活性最低。DPPH·清除率与黄酮含量(R2=0.7300)和多酚含量(R2=0.6675)显著相关,总还原力与多酚含量显著相关(R2=0.8234)。

Magnolia liliflora was pretreated by four drying methods-shade drying,sun drying,hot-air drying and microwave drying which effect the flavonoids,polyphenols content and the antioxidant activity of Magnolia liliflora were investigated. The results showed that four drying methods had the different dehydration speed and drying time. Compared to the other drying methods,microwave drying could effectively reduced moisture. Drying rate was influenced by drying methods which followed the order:Microwave drying > hot-air drying > sun drying > shade drying. Addition,treatments of shade drying,microwave drying(900 W)and hot-air drying(50 ℃)exhibited the higher values of flavonoids,polyphenols content and antioxidant activity. However,treatments of sun drying exhibited the lowest values of antioxidant activity because of the lower vaules of flavonoids and polyphenols content. DPPH· scavenging rate had significantly correlated with flavonoids and polyphenols content the correlation coefficient are R2 = 0.7300 and R2 = 0.6675,respectively. Polyphenols content had significantly related with total reducing power(R2 = 0.8234).