Effect of replacing wheat flour with mung bean flour on the texture, physicochemical and sensory properties

Increasing demand for various quality food products with health-related properties has caused many efforts to be made in producing such products. Cereal industry is among major industries with the potential of attracting people’s attention in this regard. However, staling and lack of fiber and other nutritients in flour is a problem with the products of this industry. Mung bean belongs to Fabaceae family. Mung bean has 7.91% water content, 24.08% protein content, 1.55% fat content, 2.87% ash content, 2.20% fiber content, and 25.73% starch content. In addition, Mung bean has bioactive compounds like tannin, phytic acid, flavonoid, phenolic acid, and other organic acids. This bean is cultivated in Asia, Australia, New Zealand, and Africa.

In this study, mung bean powder was used in the formulation of sponge cake. The ingredients used in the formula were flour, cake liquid oil, sugar, fresh eggs, dry milk powder, baking powder, whey protein, vanilla and water. Mung bean flour replacied wheat flour by 0, 25, 50, 75, 100% in the sponge cake formula. The traditional sponge cake formula in this study was adopted from the work of Ataei Nukabadi and Hojjatoleslamy (2017). Sugar and oil were mixed for 5 min; the eggs were then added and mixed on the speed 3 setting for 5 min. The sifted powder materials and mung powder were gradually added into the mixer on speed 3 setting for 5 min. For each cake, 58- 60 g of cake batter was poured into a cake pan (50 g) and baked at 250- 280°C for 20 min in preheated oven. The cakes were allowed to cool for 1 hour and then the cooled cakes were packed in poly propylene bags at room temperature before performing physicochemical and sensory evaluation. Chemical evaluation including moisture content, crude protein, ash, crud fat, density, wet gluten, were measured on the sponge cakes according to their standards. Texture profile analysis (TPA) of the cake samples from the midsection of the cakes was carried out using a texture analyzer on the first and thirtieth day of storage and Hardness, cohesiveness, cut, punch and springeness were also measured. Hunter Lab and a*, b*, L*, ∆E was used for color measurements of samples. The hedonic scale is a unique scale providing both reliable and valid results for sensory evaluation. A 5 point hedonic scale was applied to determine the degree of overall acceptance of the sponge cakes. Twenty semi- trained panelists received five samples and were asked to rate the samples based on degree of preference on a five- point hedonic scale (one: extremely dislike, two: dislike, three: neither like nor dislike, four: like, five: extremely like). The panelists received samples from the midsection of the cakes which had been held at room temperature. Each measurement was an average value of 3 replicates. The experimental data were subjected to an analysis of variance (ANOVA) for a completely random design using a statistical analysis system. Duncan's multiple range test was used to determine the differences among means at significance level of 0.05.

The results showed that hardness, punch, density, ash and protein increased as the level of mung bean powder increased, whereas springiness, moisture content, fat and gluten decreased. There was no significant difference between the samples in measuring the cohesiveness in the first and thirtieth day. Color measurements showed that crumb a* increased and b*, L*reverse trend was observed. The value of ∆E shown sponge cake contained 25% mung had the least difference with the control sample. In sensory evaluation, 25% sample was selected as an acceptable cake formula by the panelists, based on texture, taste, odor and color. The results shown, it is possible to produce sponge cake with different percentages of replacing wheat flour by mung bean powder. Increasing mung powder up to 50% does not have any significant effect on texture and organoleptic properties.