Comparative analysis of bioactives and protein characteristics in six genotypes of yam bean tubers

Abstract

Yam bean (Pachyrrhizus spp.) is a diverse genus of high-moisture tuber crops with useful agricultural properties but limited nutritional and health benefits due to its low nutrient density. Only a few species with limited genotypic variability are produced globally, such as P. erosus (jicama), P. tuberosus (goiteño), and P. ahipa (ahipa). However, there is a deficit of compositional information on indigenous landraces, which could assist in the future selection and breeding of yam bean tubers with improved nutritional and health properties. The present study evaluated the proximate composition, protein characteristics, and some phytochemical properties of two indigenous landraces, one of P. tuberosus and the other of P. erosus. Individual tuber weight and moisture content of whole tuber were significantly higher (p ≥ 0.05) in P. erosus than in P. tuberosus samples. While P. erosus showed greater protein digestibility, P. tuberosus exhibited superior biochemical properties with respect to total phenolic content, antioxidant capacity, and ascorbic acid levels, with significant variation observed among genotypes and species. HPLC analysis further identified diverse phenolic compounds in the yam bean tuber, including gallic acid, coumaric acid, and ferulic acid. These findings provide detailed compositional data on under-studied indigenous yam bean landraces, supporting their future use in food and nutrition research.