Optimization of Enzymatic Hydrolysis Parameters of Pigeon Pea for Better Recovery of Dhal

Abstract

Pigeon pea is mostly consumed in the form of splits and it provides good source of proteins. The pigeon pea grain is considered as most difficult for dehulling as compared to other pulses owing to its seed coat which is more firmly attached with the cotyledons through a layer of gum and mucilage. Pre milling treatments are generally employed to loosen the seed coat to remove husk without losing any edible portion. The effect of four enzymatic hydrolysis parameters, i.e., enzyme concentration (20–60 mg/ 100 g dry matter), incubation time (3-15 h), incubation temperature (40-60 0C) and tempering water pH (4.0-6.0) on hulling efficiency were optimized using response surface methodology. Three enzymes i.e. xylanase, pectinase, and cellulase 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 maximum dehulling efficiency of 88.37 % at enzyme concentration; 37.80 mg/100 g dry matter, incubation time, 8.69 min, incubation temperature, 48.48 0C and tempering water pH, 5.49. The results of the predicted optimum conditions were validated experimentally. Dehulling efficiency at optimum condition was observed to be 88.12 % and showed 0.28 % deviation from the predicted values. Results of the study revealed that dehulling efficiency of enzyme treated dhal could be increased 13.81 % compared to the control, i.e., the oil treated sample.