Antinutritional factors and protein digestibility of broad bean flours hydrolysed during soaking using vacuum enzyme impregnation.

The hydrolysis of legume proteins improves their nutritional and functional properties. Usually done by mixing flour with an enzyme solution, the process can be simplified using vacuum enzyme impregnation during soaking. This study used vacuum impregnation with papain or bromelain to obtain hydrolysed broad bean flours. It examined the impact of vacuum impregnation and enzyme incorporation on hydration kinetics and the impact of hydrolysis and dehulling on antinutritional factors and protein digestibility. Vacuum impregnation accelerated hydration and enzyme incorporation did not alter the hydration rate. Maximum hydrolysis degrees were 9.1 % with papain and 8.8 % with bromelain after 4 h of soaking. Hydrolysis increased phytic acid, total phenolics, and tannins content while decreasing trypsin inhibitors. Dehulling increased phytic acid and trypsin inhibitors, reduced tannins, and enhanced protein digestibility. Vacuum enzyme impregnation during soaking was effective for hydration and protein hydrolysis, modifying the nutritional properties of broad bean flours.