Effect of soaking in sodium bicarbonate solution followed by autoclaving on the nutritional and antinutritional properties of velvet bean seeds

In the present study, the effect of soaking in sodium bicarbonate solution + autoclaving treatment on the levels of nutritional and antinutritional constituents of seeds of a South Indian underutilized food legume, velvet bean (VB) (Mucuna pruriens [L.] DC. var. utilis [Wall. ex Wight] Baker ex Burck) was investigated. This treatment was found to cause a significant reduction on the levels of various antinutritional compounds such as total free phenolics (82-83%), tannins (74-84%), L-Dopa (83-85%), phytic acid (75-78%), oligosaccharides such as raffinose (76-82%), stachyose (77%) and verbascose (75-76%), hemagglutinating activity (71-75%), trypsin inhibitor activity (81-82%), and α-amylase inhibitor activity (82-84%) of both white and black accessions of VB seeds without affecting their nutritional quality. It also resulted in significant improvement on the in vitro protein digestibility (18.7-20.1%) of VB seeds. Adoption of such viable processing method will enhance the utilization of VB seeds as an alternative/additional protein source for both human beings and animals. The seeds of velvet bean (VB) (Mucuna pruriens[L.] DC. var. utilis[Wall. ex Wight] Baker ex Burck), a South Indian underutilized food legume was reported to contain higher level of protein and other nutrients. But their utilization as food/feed remains little mainly because of the presence of high concentration of various antinutritional compounds. In the present study, the effect of soaking the VB seeds in sodium bicarbonate solution + autoclaving treatment on the nutritional value and antinutritional constituents of VB seeds were investigated. This treatment resulted in the maximum reduction of various antinutritional substances and the significant improvement on the protein digestibility of both white and black VB seeds without affecting their nutritional quality. Hence, such viable cost-effective processing method could be recommended for the effective utilization of VB seeds as an alternative/additional protein source in the diet of livestock animals.