Optimization of enzymatic hydrolysis of pigeon pea for cooking quality of dhal

Cooking quality of dehusked splits is influenced by the dehulling method, in particular, by the pre-milling treatments. The effects of four enzymatic hydrolysis parameters, i.e., enzyme concentration (20–60 mg/100 g dry matter), incubation time (3-15 h), incubation temperature (40-60oC) and tempering water pH (4.0-6.0) on cooking time of pigeon pea dhal were optimized using response surface methodology. Three kinds of enzymes, i.e., xylanase, pectinase, and cellulas were used in combination for enzymatic pre-treatment. A quadratic model satisfactorily described the dehulling efficiency with high value for the coefficient of determination R2 (0.9062). It predicted a minimum cooking time of 21.91 min at enzyme concentration of 37.8 mg/100 g dry matter, incubation time 8.69 min, incubation temperature 48.5oC and pH 5.49 of tempering water. Cooking time at optimum condition was observed to be 21.50 min and the predicted values of cooking time showed 2.19% deviation from the experimental values. Results of the study revealed that cooking time of enzyme treated dhal could be decreased by 19.77% compared to the oil treated dhal.