The present study aimed to optimize the relative proportion of roasted flax seed flour as dietary fiber ingredient (DFI) and jaggery:stevia percent in preparation of chhana balls. Response surface methodology (RSM) was used to determine the optimum DFI proportion and jaggery:stevia percent. Thirteen experimental runs were conducted with varying levels of independent variables viz. dietary fiber ingredient (4.0-8.0%) and jaggery:stevia :: 1:1 (22.5-27.5%), as generated by central composite design. The responses investigated were pH, cooking yield, water activity (aw), Hue angle, Chroma value and sensory attributes of chhana balls. The RSM results showed that the experimental data could be adequately fitted to a second-order polynomial model with a satisfactory Coefficient of determination (R2 > 50%). The study revealed that the effect of all the factors were significant on the studied responses. The optimum formulation obtained using desirability function was 5.92 and 26.42% for DFI proportion and jaggery:stevia respectively. The values of responses at optimum formulation were 6.36 pH, 91.80 cooking yield (%), 0.9481 water activity (aw), - 22.62 Hue angle, 8.71 Chroma value, 6.89 sweetness and 7.10 overall acceptability. These predicted values were validated with experimental values and found be not significantly different.
Keywords: Central composite design; Chhana balls; Dietary fiber; Jaggery; Response surface methodology; Stevia.