Effect of flour replacement with pomegranate seed powder on the properties of Sponge Cake

Increasing the demand for purchase and use of high quality products with good health benefits has led to a lot of efforts to increase and maintain the quality of different products. Sponge cake is one of the cereal products that the stale and lack of dietary fiber in cake flour is one of the major problems in this product. Cake is one of the flour mills and is intermediate in terms of calorie content of bread and biscuits. This high-consumption product has many fans among children and adolescents. Given the fact that this group of people is in the age of growth and healthy and nutritious nutrition will play a significant role in their health, the enrichment of all kinds of cakes is among the most important issues. Since the predominant promise is low-value and even unattractive and with high calories, it only causes obesity and cardiovascular disease. Recently, the use of fruit and vegetable waste has become widespread to reduce environmental pollution. Considering that these lesions are important sources of polyphenols. Industrial and agricultural residues are sources of natural antioxidants and food fibers. The functional properties of some skin components, such as pectin, flavonoids, carotenoids, lemonies, and poly-methoxyflavones, should be taken into account. Nowadays, cake producers have a major problem with lipid oxidation, which limits the shelf life of their products. Bakery products such as cakes, especially those with high fat content, tend to become corrosive after prolonged storage due to unsaturated fatty acids. Special attention has been paid to the use of natural antioxidants to minimize the use of synthetic additives. In recent years, the growing trend of bakeries with nutritional value such as rich fiber has been observed. In order to increase fiber content in cake and muffins, several raw materials such as bran, outer layers of grains have been used.

Pomegranate was purchased freshly from the market, then the seeds were separated, then the samples were dewatered and the cores were dried at 30 ° C for 2 days. The pomegranate cores were dried after milling and after passing the sieve with the mesh 35 was used. The dough was prepared and the pomegranate and xanthan gum flour was added to the dough. The prepared dough was poured into the mold, then the molds were bake for 30 minutes in an oven at 175 ° C. Cakes were then stored after leaving the oven and cooled in polyethylene packages at room temperature until further tests were performed. An image processing method was used to check the porosity and color of the crust and crumb of enriched cakes. For this purpose, the imaging was carried out in a special box with a uniform white light at all directions and from a fixed distance with the Canon Power Shot P500 Canon Camera. Pictures are saved in JPG format. To get the same levels from each image, Adobe Photoshop CS4 (Photoshop CS6) was designed with 457 x 504 pixels for the brain and skin. To colorize the samples, the RGB color space was converted by Image J software to * L,*a, and *b. In this research, the effect of replacing wheat flour with pomegranate powder (0-50%) and xanthan gum (0 to 0.3%) on the physico-chemical (Moisture, pH, ash, porosity, volume index, fiber and protein), qualitative (Density, stiffness, weight loss, symmetry, volume, color and durability) and sensory properties of cake were evaluated using the response surface method in the form of a composite design.

The results of this study showed that increasing the replacement of pomegranate powder has a positive and significant effect on fiber content, protein and weight loss and negative effect on density properties, texture stiffness, symmetry, volume index, color indices, the overall acceptance and flavor of the samples. Also, increase in the percentage of xanthan gum has a positive and significant effect on density, texture stiffness, volume, porosity, and volume index and weight loss of samples. In general, the evaluation of all characteristics showed that the cake sample containing 0.1% gum and 22.22% pomegranate powder had the best quality. On the other hand, comparing the optimal sample and the control indicates that the replacement of pomegranate powder has increased the phenolic compounds and reduced peroxide value.