The purpose of this study was to determine the optimal recipe of rice cookies with two different amounts of Stevia rebaudiana leaf and grape seed oil, using a central composite design (CCD). In addition, mixing conditions of rice cookies were optimized by sensory evaluation and mechanical and physicochemical analysis using response surface methodology (RSM). RSM was used to obtain 10 experimental points (including two replicates of Stevia rebaudiana leaf and Grape seed oil), and the formulation of Stevia rebaudiana leaf added rice cookies was optimized using rheology. The results of mechanical and physicochemical analysis showed significant values for lightness, redness, yellowness, hardness, spread factor, loss rate, leavening rate, sweetness, moisture, pH, and density (P<0.001), results of the sensory evaluation showed significant values for color, flavor, taste, texture, appearance, and overall quality (P<0.05). As a results, optimal sensory ratio was found to be 1.98 g of Stevia rebaudiana leaf and 37.94 g of Grape seed oil.
Hardness ; Hydrogen-Ion Concentration ; Rheology ; Stevia* ; Vitis

This study was carried out to evaluate the effects of stevia (Stevia rebaudiana Bertoni) leaf powder on soybean milk quality. Soybean milk was prepared with the addition of 0.1 g (SP1), 0.2 g (SP2), 0.3 g (SP3), 0.4 g (SP4) of stevia leaf powder. The pH of soybean milk added with stevia leaf powders ranged from 7.90 to 7.98, whereas that of control was 7.88. The viscosity of soybean milk added with stevia leaf powder was 11.13~12.71 cp while that of control was 11.09 cp. Soymilk added with stevia leaf powder yielded values of Hunter L (59.40~64.94), a (-7.63~-6.45), and b (18.71~19.63), whereas that of control were 67.45, -4.74 and 20.13, respectively. There was decrease upon addition of stevia leaf powder. During storage, the pH, viscosity, L, and b values were decreased continuously. According to sensory evaluation, taste, and flavor of SP3 were better than the other groups. Quality characteristics between control and SP3 showed no significant differences. Therefore, this study showed the possibility of substituting 0.3 g of stevia leaf powder instead of sugar for creating a standard quality soybean milk with low calories. Upon the results of this study, it may be assumed that there are consequences positive responses to health-oriented consumers when using stevia leaf powder.
Hydrogen-Ion Concentration ; Milk* ; Powders ; Soybeans* ; Stevia* ; Viscosity