Purple sweet potato [Ipomoea batatas(L.) Lam.] abundant in natural eatable pigments is a distinctive variety of sweet potato.Since Chuan Shan Purple being cultivated in Japan MAFF Kyushu Agriculture Test Site in the early 1990s,purple sweet potato has being widely extended in Japan and other developed countries for it is characteristic of having nutritive components and a variety of medicinal function,such as anti-oxidation,preventing and curing angiocardiopathy,and so on.According to researches on aspects ...