Optimization of sweetener formulation in sugar-free yoghurt using response surface methodology

The sweetener combinations played an important role in yoghurt making. In this study, we investigated the effects of rebaudioside A, erythritol, and isomalto-oligosaccharide (IMO) combinations on sensory score, hardness, consistency, viscosity, pH, and water-holding capacity of sugar-free yoghurt. A central composite rotatable design (CCRD) was adopted to obtain data for the correlative statistical models. Through the response surface analysis, the optimum formulation conditions of sweetener combinations were obtained by superimposing sensory properties, texture, pH, and water-holding capacity data, i.e. rebaudioside A 0.2 g/kg, erythritol 18.09 g/kg, and IMO 29.08 g/kg. In this condition, the quality of the yoghurt was acceptable, shown as harmonious taste, reasonable pH, exquisite texture, and high water-holding capacity.