Optimization of Curd Yogurt Production Using Saccharified Rice Solution by Response Surface Methodology

Abstract

Abstract This study was carried out to establish the optimal conditions for curd yogurt using saccharified rice solution. A central composite design was applied to investigate the effects of pectin (2.8~8.4 g), skim milk (14~70 g) and oligosaccharide (28~84 g) ratio on the physicochemical and sensory characteristics of curd yogurt using saccharified rice solution. pH, total acidity, and color value, were analyzed and sensory evaluation was performed. The pH of curd yogurt decreased with decreasing pectin and oligosaccharide ratio . The addition of pectin had a significant effect on the viscosity while skim milk had a significant effect on the color value (a and b value). The results of sensory evaluation showed that, oligosaccharide and skim milk had significant effects on sweetness and sour taste. Oligosaccharide and skim milk masked the sour taste of curd yogurt. The optimum range of ingredients for curd yogurt using saccharified rice solution was predicted to be 4.27~4.90 g of pectin, 3 0.80~41.30 g of skim milk, an d 28.00~36.10 g of oligosaccharide. Based on the overlapped results of physicochemical and sensory evaluation, the optimal amounts of pectin, skim milk and oligosaccharide were 4.59 g, 36.50 g and 32.05 g, respectively.Key words: central composite design, saccharified rice solution, curd yogurt, optimization point