Cell walls limit in vitro protein digestibility in processed legume seeds

Legume seeds were treated in various ways, e.g. cooking applied either before or after milling, in order to obtain flours with different microstructural properties. In vitro protein digestibility was assessed by a pepsin/pancreatin index. In all cases digestibility was enhanced by cooking, although final values varied depending on the flour preparation procedure. Cooked and milled seeds, which retained intact cell walls, showed lower digestibility indices (58-72%) than sonicated or milled/cooked preparations devoid of such structures (77-89%). Results suggest that naturally occurring physical barriers, such as cell walls, may reduce the bioavailability of legume proteins.