Effect of germinated soybean flour and ultrasonic wave on physicochemical and sensory properties of gluten-free rice cake

The objective of this study was to investigate the effect of replacing of rice flour with different ratio (0, 10 and 20 % w/w based on rice flour) germinated and non-germinated soy flour with ultrasonic pretreatment (0, 4, and 6 min) on the cake batter on the physicochemical and sensory characteristics of rice cake. A factorial experiment with a completely randomized design with three replications was used for data analysis. The use of germination soy flour in rice cake formulations and ultrasonic pretreatment on batter cake, significantly improved the technological characteristics and sensory attributes of the samples (p< 0.05). Compared with the non-germination soy flour, the germinated groups had higher contents of moisture, protein, fiber, and also improved volume, porosity and softness, significantly (p< 0.05). The sample formulations containing of 20 % w/w germinated soy flour with ultrasonic pretreatment for 6 min indicated the highest ranked of the technological characteristics (volume, porosity, and firmness) and sensory attributes (texture and overall) and unfortunately showed a higher darkness (L value) and redness (a value) and received low sensory scores of tastes and color compared to the other sample and control. The optimized formulation for the technological characteristics (volume, porosity, and firmness) and all sensory attributes preference had a germinated soy flour content of 10% with ultrasonic pretreatment for 6 min (p< 0.05). These achievements will pave the way for using the combination technologies involving the germination treatment with sonication pretreatment for improving physicochemical and sensory characteristics of cake produced by gluten-free flour blend.