Process optimization of partially hydrolyzed guar gum using response surface methodology

Process variables for maximum viscosity reduction of guar gum were studied using response surface methodology. Central composite design with four independent variables: pH, temperature, reaction time and enzyme concentration was used to study the response variable i.e. viscosity. The experimental values of viscosity ranged between 14 and 348 cPs. The second-order model obtained for viscosity values revealed coefficient of determination of 0.9629. The optimum conditions for enzymatic hydrolysis of guar gum were obtained with 0.19 mg/g enzyme concentration, 5.59 pH and 3.99 h hydrolysis time at 49.84 degrees C. Confirmatory studies revealed that guar gum soluble fibre of very low viscosity i.e. 10 cPs (1 cP = 0.001 Pa.s) was obtained with enzymatic hydrolysis under optimized conditions of process variables.