Nutritional and functional attributes of mungbean (Vigna radiata [L] Wilczek) flour as affected by sprouting time

Abstract

Sprouting of grains improves their nutritional value and functionality, but information on the appropriate sprouting time required to obtain an optimum quality of mungbean flour is limited. This study evaluated the attributes of mungbean flour as influenced by sprouting time. Mungbean seeds were cleaned, sorted, surface-sterilised, rinsed and sprouted (28°C and 26% R.H) for 24 to 120 hr. Proximate, amino acids (AA), vitamins, mineral, anti-nutritional (phytate, tannin, oxalate, trypsin inhibitor, raffinose and stachyose) composition, functional properties (viscosity, bulk density and swelling index), microbial quality (total plate and mould counts) and energy of the flours obtained from the sprouted seeds were analysed. Data were subjected to analysis of variance and the means separated by Duncan's Multiple Range Test. Significant (P < 0.05) differences were observed in the energy contents, chemical and functional properties of mungbean flour. There was no fungal growth in the samples until after 72 hr. Leucine, followed by lysine, was the dominant essential AA while methionine was the least. In conclusion, increase in sprouting period improved the nutrient composition but reduced the anti-nutrients of mungbean flour. Samples sprouted for 24 hr had the highest total essential and conditionally essential AA.