Process optimization for a nutritious low-calorie high-fiber whey-based ready-to-serve watermelon beverage.

Whey is a nutritious by product of some traditional Indian processed milk products and it needs to be utilized in an effective way in order to reduce environmental hazards associated with its untreated disposal. Low calorie watermelon beverage appears to be a simple, attractive and economic method of whey disposal. The experiment was designed by Central Composite Rotatable Design of Responce Surface Methodology. Three independent variables whey, Innova ® fiber and sucralose were chosen at five levels within the respective ranges of 40-60 %, 2.0-5.0 % and 0.01-0.03 %. The effect of the variables on flavour, mouthfeel, after-taste, viscosity, total soluble solids (all to be maximized) and sedimentation (to be minimized) was observed. These three were the independent variables whose effect on flavour, mouthfeel, after-taste, viscosity, total soluble solids (all to be maximized) and sedimentation (to be minimized) were evaluated. Quadratic model fitted well to all dependent variables. The R(2) values for flavour, mouthfeel, aftertaste, viscosity, sedimentation and TSS were 95.57, 98.71, 95.50, 97.87, 99.26 and 98.17 %, respectively. Response surface methodology was used to optimize the level of processing parameters. Maximum scores for flavour (7.46), mouthfeel (7.49), after-taste (7.72), viscosity (13.55 cp) and total soluble solid (15.34°Brix) and minimum score for sedimentation (1.55 ml/10 ml) were obtained when the formulation contained 51.46 % whey, 3.84 % Innova® fiber and 0.021 % sucralose.