Effect of Various Processing Methods on Antinutrients andin VitroDigestibility of Protein and Starch of Two Chinese Indigenous Legume Seeds

Abstract

The effect of various processing methods on antinutrients and in vitro protein and starch digestibility of Phaseolus angularis and Phaseolus calcaratus seeds was studied. The processes, which included soaking (12 and 18 h), cooking, autoclaving, and germination (24 and 48 h), significantly reduced (p < 0.05) the levels of antinutrients including phytates, tannins, trypsin inhibitors, and amylase inhibitors and significantly improved (p < 0.05) the digestibility of protein and starch as well. Since a significant negative correlation (ranging from −0.80 to −1.00) was found between these antinutrients and the digestibility of both protein and starch, the reduction in the levels of these antinutrients might partly account for the improved digestibility. Cooking as well as autoclaving brought about a more significant (p < 0.05) improvement in the digestibility of both protein and starch as compared with soaking and germination. In this study, all processing methods were more effective in improving the starch d...