Thermal heat processing effects on antinutrients, protein and starch digestibility of food legumes

Thermal heat processing effects were investigated on antinutrients, protein and, starch digestibility of black grams, chick peas, lentils, red and white kidney beans. The tannin and phytic acid contents in these five food legumes ranged from 770-1100 mg/100 g to 970-1440 mg/100 g, respectively, whereas protein and starch digestibilities of the raw food legumes were 33.0-37.6% and 36.8-42.0%, respectively. Reduction in the levels of antinutrients, along with an improvement in protein and starch digestibility, was observed after cooking these food legumes. Antinutrient, including tannin (33.1-45.7%) and phytic acid (28.0-51.6%) contents, were reduced by different thermal heat treatments (121AC10, 121AC20, 121AC40, 121AC60, 121AC90, 128AC20). Maximum improvement in protein (95.7-105%) and starch (117-138%) digestibilities was observed on cooking these food legumes at 121 °C for 10 min (121AC10). However, ordinary cooking resulted in improvement of protein and starch digestibilities of the food legumes by 86.0-93.3% and 84.0-90.4%, respectively.