Active components and mineral elements analysis of three kinds of Chinese yam

To investigate the active component of different yam varieties, three commercially available yam varieties were collected and used in this research.The total polysaccharide and saponins were analyzed. ICP-OES was used to determine the mineral element in these three yam varieties.The results showed that the total saponins were ranging from 0.01% to 0.05%, in an ascending order as Dioscorea fordii, Dioscorea opposita, Dioscorea alata. And their total polysaccharide was ranging from1.14% to 3.82%, respectively, in a descending order. Content of mineral elements in these three yam varieties was different.Especially, Dioscorea opposita was rich in selenium ( 205.0 μg/kg) , while Dioscorea fordii and Dioscorea opposita were rich in zinc, which were 3.9 mg/kg and 4.1 mg/kg, and this content was higher than national average. Therefore, Dioscorea fordii was rich in saponins, while Diosocorea alata was rich in polysaccharide. And Dioscorea opposita was rich in both saponins and polysaccharide as well as mineral elements, especially in selenium. According to this result, they can be used for different purpose.