Nutritional, Antioxidant and Antimicrobial Properties of Underutilized Yam Species Grown in Sri Lanka

Abstract

Underutilized food crops, with good nutritional potential and easily cultivable characteristics, have been recognized as one of the promising solutions for the world food crisis. Substantial number of underutilized yams that are grown under natural climatic condition with little or no-input are available in Sri Lanka. But little is known about their nutritional and functional values. This research attempted to investigate those properties of widely grown eight yams available in Sri Lanka. It includes six yam cultivars of Dioscorea including Rajala, Kahata Angala, Dandina, Higurala and Seeni Ala and two aroid cultivars Kidarang (Amorphophallus campanulatus) and Kiri Ala (Xanthosoma sagittifoliu). Selected varieties were tested for proximate composition (moisture, crude protein, crude fat, crude fiber, ash and carbohydrate), mineral composition (Fe, Cu, K, Zn, Na, Mg and Ca), antioxidant capacity, antimicrobial activity by using AOAC officially approved methods, Atomic absorption spectrometer, total phenolic content assay, DPPH radical scavenging assay and agar well diffusion method respectively. The data obtained were analyzed by performing ANOVA using Minitab 17 statistical software. Highest values for the proximate and mineral composition were observed in Kidarang. Highest antioxidant capacity was observed in Dandina. Rajala was effective against pathogenic microorganisms. Generally, all studied varieties were found to be rich in nutritional and functional characteristics. Therefore, it is recommended to promote the consumption of those varieties among Sri Lankan consumers as healthy foods.