Production and characterization of low-calorie orange nectar containing stevioside.

The study was carried out to produce and characterize a low-calorie orange nectar using response surface methodology (RSM). To optimize the formulation, three different levels of independent variables; sugar, stevioside and pectin and two responses of Brix and viscosity were selected. In the optimum formulation, sugar content reduced to 70 % (compared to control sample) using stevioside and pectin with maximum levels of 0.06 and 0.03 %, respectively. Physicochemical properties of optimal and control samples were determined at refrigerated (4 °C) and ambient (25 °C) temperatures for 2 months. At refrigerator, the reduction rate for stevioside was 5 % while a decrease of 18 % was observed at ambient temperature. The vitamin C content in low-calorie orange nactar was 13.4 % higher than control sample at both temperatures. Thus the production of low-calorie orange nectar using stevioside could be industrially feasible and recommended to people who looking for dietetic foods.