Background and Objectives: Reduction or elimination of sugar from dairy dessert formulations is in relation to the safety of people and has important nutritional quality. But sugar elimination from food formulations results to the some problems that should be solved with application of sutiable texture improver(s).
Materials and Methods: The effects of different levels of corn starch (3, 4.5, and 6%), gelatin (0.2, 0.4, and 0.6%) and substituting date syrup (17,19.5, and 22%) instead of sugar on the physical and chemical properties, as well as textral and sensory attributes of dairy dessert were investigated. RSM was selected and the Central Composite Design with 5% probabality was chosen.
Results: The effect of gelatin and date syrup on the Brix of dairy dessert  was significant. The viscosity of the samples increased significantly (P<0.05) with the increase of starch and gelatin. Effect of starch was more than gelatin, but date syrup had no significant effect on viscosity. In case of texture (hardness and adhesion), all dessert samples had smiliar trend to viscosity results. All samples had little or no serum separation. Starch, gelatin and date syrup had no significant effects on L* factor, but their effect on a* and b* parameters was significant (P<0.05). The sensory evaluation results demonstrated no significant difference between all samples and the scores determined in the range of 3.13-4.30. All samples were negative for yeast, mold and E.coli. The total count was 10-30 cfu/g, therefore, it is acceptable.
Conclusions: RSM is a sutiable and reliable method for optimizing dairy dessert and predicted the best condition, including: 3% starch, 0.2% gelatin and 27.9% date syrup. In these conditions, pH, TSS, overall acceptability, hardness and adhesiveness were 6, 29.8, 3.7, 63.7 and 57.6 g.sec values, respectively.