Nutritional quality evaluation of velvet bean seeds (Mucuna pruriens) exposed to gamma irradiation.

摘要

Effects of gamma irradiation on velvet bean (Mucuna pruriens) seeds at various doses (0, 2.5, 5, 7.5, 10, 15 and 30 kGy) were investigated on their proximate composition, mineral constituents, amino acids, fatty acids and functional properties. Gamma irradiation resulted in a significant increase in crude protein contents at all doses, while crude lipid, crude fibre and ash contents showed a dose-dependent decrease. Raw velvet bean seeds were rich in minerals (K, P, Ca, Mg, Fe and Se). Na, Cu and Mn were significantly decreased by irradiation at all doses, while Mg and Fe showed a significant decrease only above 10 kGy. The essential amino acids in raw and gamma-irradiated Mucuna seeds were comparable with the FAO/WHO recommended dietary intake pattern. A significant increase in in vitro protein digestibility was seen in seeds irradiated at 30 kGy. Amounts of unsaturated fatty acids were high in Mucuna seeds, but decreased significantly after irradiation. However, linoleic acid was not present in raw seeds but was detected after irradiation and was elevated to a high level by treatment at 30 kGy. Behenic acid, a major anti-nutritional factor, was reduced significantly by irradiation. Significant enhancement in water absorption and oil absorption capacities, protein solubility, emulsion activity and improvements in gelation capacity were recorded after irradiation. Results suggest that gamma irradiation does not affect the overall nutrient contents of velvet beans, and, therefore, can be used as an effective method of preservation.