Freeze-thaw procedure as an alternative method to reduce the cooking time of Jack bean (Canavalia ensiformis (L.) DC) while retaining its nutritional quality

Abstract

This study explored the effect of freeze-thaw procedures on the Jack bean’s cell wall, cooking times, and nutritional quality.Confocal laser microscopy was used to examine bean’s microstructure. Optimal cooking times, hemagglutination activity, and mineral content were evaluated on beans subjected to freeze-thaw procedures and those cooked with sodium bicarbonate (AC) and demineralized water (DC). The freeze-thaw procedure that yield the largest reduction in cooking times, AC, and DC samples were used for in vitro protein and starch digestion.Freeze-thaw procedure at -20 °C for 24 h resulted in the biggest enlargement of intercellular spaces and the largest reduction in cooking time although it was less effective compared to alkaline salt cooking. No hemagglutination activity was observed in any cooked beans and mineral loss was correlated with duration of cooking times. Protein digestibility increased in freeze-thaw treated beans compared to control beans cooked in demineralized water, with no effect on starch digestibility. The findings suggest that enlargement of intercellular space due to freeze-thawing treatment can reduce cooking times and that the shorter duration of cooking may increase protein digestibility. The absence of hemagglutination activity and the observed mineral loss emphasize the importance of efficient cooking methods in preserving nutritional properties.