Assessment of diversity in anti-nutrient profile, resistant starch, minerals and carbohydrate components in different ricebean (Vigna umbellata) accessions

Abstract

Ricebean accessions (n = 38) cultivated in India were evaluated for their comprehensive nutrient, anti-nutrients and mineral composition. Protein and total dietary fibre ranged between 23.23 and 27.33 and 12.27 to 16.69 g/100 g, respectively. Among the oligosaccharides, verbascose was not detected, however, raffinose and stachyose ranged between 47 and 186 and 117 to 5765 mg/100 g, respectively. Among the free sugars, sucrose was found dominating (up to 370 mg/100 g). Resistant starch (4.13 to 8.62 %), iron (3.49 to 7.46 mg/100 g), zinc (1.90 to 3.72 mg/100 g) and selenium (0.28 to 4.48 µg/100 g) varied significantly (p < 0.05) among ricebean samples. Phytic acid, saponin, trypsin inhibitor and oxalate analysed in ricebean accessions ranged between 303 and 760 mg/100 g, 19 to 46 mg/g, 309 to 1076 mg/100 g and 219 to 431 mg/100 g, respectively. Multivariate analysis using hierarchical clustering analysis (HCA), and principal component analysis (PCA) was employed to decipher the diversity of nutrients and anti-nutrients across the ricebean accessions. Based on HCA, dendrogram-1 (nutrients) and dendrogram-2 (minerals, anti-nutrients) were produced, having four clusters in each. In the dendrogram-1 and 2, the largest cluster had (n = 21) and (n = 15) accessions, respectively. The PCA analyse the uncorrelated set of variables (principal components) and it condenses a large set of data variables. Based on the eigenvalue >1, a total of eight PCs were formed contributing total variance of 78.8 %. The factor loading contribution in the PC1 and PC2 were from iron, fructose, glucose, raffinose and total dietary fibre, selenium (Se) and protein, respectively.

Keywords: Anti-nutrients; Free sugars; HPLC; Minerals; Phytic acid:minerals molar ratio; Resistant starch; Ricebean.