چكيده لاتين :
Introduction: The limitations of agricultural resources, the upward trend in population and environmental pollution caused by food processing remaining, have attracted researchers to make optimal use of these wastes. The bakery industry is one of the largest food industries in the world. Products like biscuits, muffins and cakes are one of the most popular products, due to their ease of eat and storable. Nowadays, one of the main problems is malnutrition of the protein. Of course, this critical issue depends on factors such as resident's growth rates, inadequate agricultural production, and the limited availability of high-quality protein sources. Thus, to fix this problem, protein-rich sources and cheap have attracted the attention of researchers (Burns et al., 1972). Sesame flour after extraction fat is rich in protein, methionine, calcium, phosphorus and niacin (Jahandideh etal.,2015). Soluble Soybean polysaccharide is a water-soluble polysaccharide that is extracted and refined from the soybean beans. Hence the aim of this study was to study the effect of addition sesame meal flour and soluble soybean polysaccharide in order to improve the structure and nutritional properties of cupcake.
Materials and methods: In this study, the use of sesame meal flour and soybean soluble polysaccharide were studied in order to improve the structure and nutritional properties of cupcake. In this research, the sesame meal flour at range of 0 to 20% replacing of wheat flour, and soluble soybean polysaccharide at range of 0 to 2%, were used in cake formulations. Sugar-batter method was used to prepare the dough. Components used in cakes formulation were consisted of 100g of wheat flour, 72g of sugar, 1.34g baking powder, 57g oil, 72g eggs, 2g nonfat dried milk powder, 4g whey powder and 25g water. The dough was poured via funnel to pans with a diameter of 8 cm. Then the pans were placed in an oven at 175C for 40 minute. For cooling, let pans for 40 minute being in the environment, and then pack in polyethylene bags. All tests on the treatments were done on the same day of baking. First, the chemical tests including moisture, ash, fiber and pH were conducted on the sesame meal and wheat flour. Then Cake moisture content was determined by drying samples at 103±2°C in a hot air oven. The weight loss calculated by measuring difference of weight before and after baking. pH was measured by a digital pH meter. The volumes of the cake samples were measured by the seed displacement method. Ash was measured by AACC 08-01, fiber by AOAC 43-991, protein by a kjeldahl method and peroxide value based on the method by Shantha and Dicker (1994). Textural properties (hardness and cohesiveness) of cupcake samples were measured by a texture analyzer (Micro stable system, UK). Prepared product based on optimized formulation according to the results of chemical and physical analysis was evaluated in moisture, protein, ash, fiber, volume, textural properties and peroxide value and its results were compared to the control sample. Data was analyzed according to the response surface methodology (RSM) in central composite design by MINITAB software (version 16), and the means were compared by Fisher's test at 5 significance percent level.
Results and discussion: The finding showed that by increasing the of sesame meal flour in formulation, moisture of sample decreased, this result is probably due to lower moisture of sesame than wheat flour and protein may be partially damaged during the process extraction, which caused the reduction in the water holding capacity of proteins. Also weight loss of cake increased, because of damaged of protein during the process extraction, which caused the reduction in the water holding capacity of them. Ash of the cupcake was better by increasing the enrichment. The ash content of sesame meal was measured to be 12.39%, which may indicate the positive effect of sesame meal on the ash content of cakes. Similarly, hardness enlarged significantly with increasing replacement of wheat flour with sesame meal. The possible reason for this result was due to the presence of high protein in sesame meal, which caused the strength of gluten bonds in dough. pH and cohesiveness decreased by increasing the sesame meal. Decomposition of residual oil in sesame meal and production of fatty acids can reduce pH. The decrease in cohesiveness may be due to the addition of sesame meal to a dense matrix in the cake and thus the samples are unable to return to their original state after deformation. Adding sesame meal increased the volume by 10% but decreased with increasing sample replacement. The reason for the increase in volume due to the addition of sesame meal in small quantities is because the fat in the mix causes the air to be confined between the layers of dough, which is expanded during baking and increases the volume of the final cake. However, high amounts of this additive impair the formation of the optimal gluten network due to the increased fiber and protein to gluten ratio. So that the dough strength in the storage of the volatile gases is reduced and the volume of the products is reduced. On the other hand, increasing soluble soybean polysaccharide often did not have a significant effect. Finally, the optimal sample based on the physicochemical characteristics was introduced a cupcake with 9/29% sesame meal flour and 1/87% soluble soybean polysaccharide. During storage, moisture migrates from the crumb to the surface and evaporates from the surface of the product. In addition to the inability of sesame meal to retain moisture, it appears that the amount of fiber resulted in the breakdown of the gel network in the cake, thereby intensifying evaporation and reducing the optimum sample moisture content. Comparison of textural features of optimum and control samples during storage was indicated the optimal cupcake was softness texture than control sample. The optimal sample had significantly higher protein and fiber content, also the volume of it increased significantly. Peroxide value of optimal sample during storage was less than of control sample. It can be concluded that wheat flour could replace with sesame meal flour to improve textural and nutritional value of cupcakes.
