Antioxidant Abilities and Compounds of Extractions from One Kind of Taiwanese Yam (Dioscores alata)

Abstract:

The effects of drying and extraction processes on the antioxidant compounds and antioxidant activities of one kind of yam（Dioscorea alata）， were investigated. The antioxidant compounds analyzed the phenolic content. The antioxidant measurements included a ，a-diphenyl-b-pricryl-hydrazyl（DPPH） radical-scavenging activity and reducing power . The 50% ethanolic extracts from the freeze-dried peel had the most antioxidant compouds and the highest antioxidant activities. Generally speaking，freeze-dried yam maintained higher antioxidant activities than hot air-dried ，the peel had more than the meat，Among three extraction methods，50% ethanolic extraction was the best.By HPLC analysis showed that the major polyphenols of the extraction was chlorogenic acid. Meanwhile tested the 50% ethanolic extracts on the inhibition of the formation of ROS，we got the same resulet as before.