Optimization of formulation of compound Chinese yam and purple sweet potato jelly by Response Surface Methodology

To develop an optimal processing formula of compound Chinese yam and purple sweet potato jelly,central composite design combined with response surface methodology was used for examining the interactive effects of amounts of complex raw material( Chinese yam ∶ purple sweet potato = 1 ∶ 1.5),complex gum( carrageenan ∶ konjac gum = 1 ∶ 1) and citric acid on the sensory quality of jelly. The results showed that experimental sensory score of the jelly was 94,which was close to the predicted value of 95,under the optimized conditions: complex raw material 1.63%,complex gum 0.46% and citric acid 0.17%. Meanwhile,the jelly was charaterized by a balanced sweet and sour taste,alluring color and unique flavor with soluble solids content of21.5% and total acidity of 0.2%. Therefore,it is feasible to optimize the process of compound Chinese yam and purple sweet potato jelly using response surface methodology.