The optimization of prebiotic sucrose-free mango nectar by response surface methodology: The effect of stevia and inulin on physicochemical and rheological properties.

The reduction of sugar consumption is one of the major challenges for nutritionists and food industry. Therefore, it is significant to replace sucrose with other types of sweeteners, especially, natural ones. The aim of the present study is to produce low-calorie, sucrose-free mango nectar and to optimize the formulation by employing response surface methodology. The two independent variables were stevia, as a low-calorie sugar replacer (0, 1.5, and 3% w/w) and inulin as a prebiotic texturizer (0, 3, and 6% w/w) in order to compensate sugar elimination defect on viscosity and °Brix. The fitted models indicated a high coefficient of determination. The results revealed that stevia and inulin are as the independent variables which had significant effects on °Brix, viscosity, and sensory scores (p < 0.05). Also, pH was affected by stevia concentration. The rheological behavior of the sucrose-free mango nectar was non-Newtonian, shear thinning as Herschel-Bulkley model which was not different from the reported behavior for normal mango nectar-containing sucrose. The optimization of the variables, based on the response surface three-dimensional plots, demonstrated that utilizing 6% w/w inulin and 3% w/w stevia produced the optimum mango nectar with the desirability of 0.85 without undesirable changes in the physicochemical and organoleptic properties. The optimum sample was produced in triplicate to validate the optimum model as well.