Nutritional, anti-nutritional and physico-functional properties of wild edible yam (Dioscorea spp.) tubers from Koraput, India

Abstract

Wild yams (Dioscorea spp.) make a significant contribution to the diets and economic welfare of tribal people of Koraput, India. However, there is a lack of information on the food quality of the tubers. The present study was carried out to evaluate the proximate, nutritional and anti-nutritional compositions as well as the physico-functional properties in 8 wild and one cultivated Dioscorea species. The proximate compositions, i.e., moisture, ash, fat, fiber, and crude protein content of yam tubers ranged from 54 to 83, 2.5 to 5.4, 0.56 to 2.0, 1 to 2.02 and 5.4–10.3% respectively. The mineral composition ranged from 31.4 to 89.4 mg 100 g−1 of sodium, 0.83–1.36 g 100 g−1 of potassium, with significant amounts of vitamin C and E. In addition, some wild species showed better nutritional and physico-functional parameters in comparison to the cultivated ones. Furthermore, the anti-nutritional compounds such as diosgenin, amylase- and trypsin-inhibitors were also significantly higher in some wild Dioscorea species. The biochemical characterization with multivariate data analysis led to a feasible classification of the usage of wild yam species. Taken together, the wild species, such as D. oppositifolia, D. hamiltonii and D. pubera showed better nutritional composition than the other yam species. The study also suggested that these wild yam species are a safe food source for local consumption and domestication, leading to potential improvement of food security.