Phytochemical and Antioxidant Analysis of Fermented ‘Dayak’ Wild Yam (Dioscorea hispida Dennst), Purple Yam (Dioscorea alata) and Air Potato (Dioscorea bulbifera L.) Tuber Flour

Abstract

Tubers of Dioscorea spp. contain many compounds that have physiological activity that can act as antioxidants and are proven to have various health uses. Antioxidant compounds have a very important role in the health of the human body. Various scientific evidence show that antioxidant compounds reduce the risk of various chronic diseases such as cancer and coronary heart disease.The study aimed to determine the phytochemical content and antioxidant activity of fermented Dayak wild yam (Dioscorea hispida Dennts), Purple Yam (Dioscorea alata var. Purpurea) and Air Potato (Dioscorea bulbifera) tubers flour was carried out. Phytochemical testing was carried out by the Harborne method (1987) and antioxidant activity using DPPH (1,1-diphenyl-2-picrylhydrazyl) method. The data obtained were analyzed descriptively from the average value of 3 replications for each parameter. Phytochemical analysis results showed the presence of alkaloids, tannins, triterpenoids and carbohydrates. While the results of the antioxidant activity testing showed that the IC50 value of fermented Dayak wild yam flour (WYF) was 227.43 ppm, air potato tuber flour (APF) was 15.77 ppm and purple yam tuber flour (PYF) was 7.70 ppm. Thus it can be concluded that all three tubers belonging to Dioscorea spp. all of them contain antioxidants with the order of the strength of antioxidant activity sequentially from the strongest to the weakest are PYF, APF and WYF.