Physicochemical and Bioactives Characteristics of Purple and YellowWaterYam(Dioscorea alata) Tubers

Abstract

This study aimed to characterize the physico-chemical properties and identify the bioactive compounds including diosgenin, water soluble polysaccharides, andwatersoluble proteins containing dioscorinfrom purple water yam(Dioscorea alatavarpurpurea) and yellowwater yam(Dioscorea alataL.). Both varieties of water yamcontainwater soluble polysaccharides that had CH3, CH2, OH, NH,C=O, acetyl (C-O), carboxyl (COOH), and C-O-C groups. WSP hydrolyzate contained more glucose. Mannose, arabinose, glucoronic acid and galacturonic acid in small quantities. Purple and yellow water yam contained 25.94 and 25.45% dioscorin from water soluble protein. The analysisof aminoacid profileshowed that the water soluble proteinofwater yam comprisesofaspartate, glutamate, serine, histidine, glycine, arginine, alanine, tyrosine, valine, phenylalanine, ileusin, leucine, andlysine. Both tubers also had diosgenin, a steroidal saponin of yam family