EFFECT OF COOKING ON PROTEINASE-INHIBITORS OF DOLICHOS-LABLAB BEAN (DOLICHOS-LABLAB-PERPUREUS L)

Proteinase inhibitory activity in ten different varieties of Dolichos lablab perpureus. L. was determined. All the varieties tested exhibite d appreciable level of proteinase inhibitory activity (PIA). The tryps in inhibitory activity (TIA) (Mean: 20170 TIU/g) was relatively higher than the chymotrypsin inhibitory activity (CIA) (Mean: 15380 CIU/g). Effect of temperature and cooking on PIA was studied. The nature of co oking medium and duration of cooking had profound effect on the PIA. T he dry fried seeds lost their PIA very rapidly (91% in 20 min). Seeds cooked in slightly alkaline medium lost their PIA quickly (89% in 30 m in) compared to those cooked in acidic (80% in 30 min) and neutral pH (83% in 30 min). The PIA in green pods was also determined and they ha d only one third of the PIA (8200 TIU/g and 8125 CIU/g) found in the d ry seeds.