Optimization of physicochemical and sensory properties of prebiotic ketchup sauce containing sweet potato puree, inulin and date liquid sugar by response surface methodology

Ketchup is a stuffing based on extract, concentrate, puree, or tomato paste which, given the increasing consumption formes of this product, it is necessary to improve the formulation using prebiotic compounds. In this study, chemical (pH, acidity, total sugar, brix and ash), physical (Synersis and color) and sensory characteristics of ketchup samples including different amounts of sweet potato puree, inulin and date liquid sugar (as a sugar substitute) was analyzed and the results were analyzed by statistical method of response surface and central composite design. The results showed that potato puree had no significant effect on chemical properties of the samples compared to two independent variables of inulin and date liquid sugar. But the linear effects and the second power of inulin and date liquid sugar were significantly different in all chemical properties compared to the control samples. The results of data analysis showed that the second power effects of potato puree and date liquid sugar variables were significant for the amount of Synersis ketchup sauce produced. The color components (L * a * b *) increased with increasing potato puree, inulin, and date liquid sugar, and the overall color difference was higher for samples containing inulin and potato puree. Sensory properties of color and general acceptance were significantly different with increasing potato puree. Except for the taste that did not have a significant effect on inulin, the increase in the amount of inulin and date liquid sugar had an influence on the other process sensory factors. Finally, this study showed that using optimum amounts of 11.25% potato puree, 3.75% inulin and 2.9% date liquid sugar as substitute for sugar, in addition to achieving physicochemical and sensory and calorie-lowering sauces also utilize functional ingredients in ketchup formulation.