Optimization of cupcake formulation by replacement of wheat flour with different levels of eggplant fiber using response surface methodology

Abstract This study aimed to design and produce optimal formula of cupcakes containing eggplant fiber by surface response methodology (RSM). The wheat flour replaced with eggplant fiber in five levels, 0-40%, whole-egg and sugar were set at the same time, 55-75% and 70-90% based on (wheat-flour + eggplant-fiber) weight, respectively. Considering the most important textural properties (hardness, cohesiveness, springiness, gumminess and chewiness), density, weight, and also by mean comparisons with Duncan's test at the level of 5% significance, optimal formulas include: formula (a) (12% eggplant-fiber, 71% whole-egg, 70% sugar) and formula (b): (8% eggplant-fiber, 57% whole-egg, 70% sugar) were appropriately suggested. Chemical properties of the optimal formulas including, protein, fat, carbohydrate, moisture, insoluble ash in acid and calorie were calculated and compared with the blank. Using of the eggplant-fiber in cupcake formulation caused calorie reduction and increased its nutritional value. Formula (b), in terms of many factors, demonstrated similarity to the blank. The eggplant-fiber had an impact on all of the textural properties except springiness. The impacts of whole-egg content on springiness, chewiness and density are also remarkable. Sugar content will be shown in weight differences and is expressed as one of the most effective variables on sample weight.