Effect of various domestic processing methods on antinutrients and in vitro protein and starch digestibility of two indigenous varieties of Indian tribal pulse, Mucuna pruriens var. utilis

The effect of various domestic processing methods on antinutrients and star ch fractions and in vitro protein and starch digestibilities of white and b lack varieties of Mucuna pruriens var. utilis was studied. Cooking or autoc laving of both raw seeds and presoaked seeds in different solutions (water, tamarind extract, sodium bicarbonate, and citric acid) significantly (p < 0.05) reduced the content of total phenolics, phytic acid, trypsin inhibito r and chymotrypsin inhibitor activities, and L-dopa compared to soaking or dry heating techniques. The germination processes (24 and 48 h) were also e ffective in the reduction of various antinutrients, although this reduction appeared to be more pronounced in a prolonged period of germination (72 h) . Water soaking followed by dehusking was found to be ineffective in the re duction of trypsin and chymotrypsin inhibitor activities in both varieties. All of the treatments were effective in significantly (p < 0.05) reducing the resistant starch content in the presently investigated samples. Cooking as well as autoclaving brought about a more significant (p < 0.05) improve ment in the digestibility of protein and starch compared to germination and dry heat treatment. Moreover, among the different processing techniques, s oaking in sodium bicarbonate solution followed by cooking (29.6-34.8%) or a utoclaving (33.0-37.2%) seemed to be the best method for improving starch d igestibility.