Application of response surface methodology in optimization of flat rice bread formulation containing sesame paste and hydroxypropyl methyl cellulose

In this study, sesame as a dietary supplement and hydroxypropyl methyl cellulose (HPMC) due to its ability to form a gel network during heating, were added to rice flour for making the flat bread. In order to determine the optimal amounts of sesame paste (in the range of 10-20%) and HPMC (in the range of 0.5-1.5%), in product formulation using response surface methodology (RSM) and central composite design (CCD), five levels of these two variables were selected and 12 baking tests were performed. Three qualitative parameters in the product, including compression stiffness, overall consumer acceptance and penetration hardness, were evaluated as responses. According to the results, sesame paste significantly (P˂0.05) reduced the quality parameters and HPMC only slightly improved them. The mathematical models obtained in this study can accurately predict the responses. Correct matching between predicted responses and the results in optimized bread, containing 10.3% sesame paste and 1.5% HPMC, indicates the high capability of RSM to optimize the formulation of gluten-free products.