1H NMR-based metabolic profiling approach to identify the geo-authentic Chinese yam (Dioscorea polystachya Turczaninow cv. Tiegun)

Chinese Yams (Dioscorea polystachya Turczaninow) are mainly used as functional food and traditional Chinese medicine in China. Adulteration is a major problem in the food and herbal industry and has affected the commercial use of natural products. Here, a 1H NMR-based metabolomics approach was used for the identification of the distinguishing metabolites between geo-authentic Chinese yam (D. polystachya cv. Tiegun plants grown in Wenxian County) and other yams. The metabolomics results suggested that the geo-authentic Chinese yam had the lowest concentrations of glucose, fructose and sucrose and the highest concentrations of leucine, threonine, arginine, glutamate, aspartate, citrate and choline among all yams tested. HPLC method confirmed the results that geo-authentic Chinese yam had lower concentrations of glucose, fructose and sucrose than the other yams. These results indicated geo-authentic Chinese yam could be verified according to the contents of glucose and fructose. And the tetrazolium solution can be used as an identification reagent for the rapid discrimination of geo-authentic Chinese yam based on the color reaction of glucose.