Effects of Fermentation Time and Steaming Intensity on the Batter Characteristics and the Quality of Mala Cake Made Using Pre-mixed Powder

The traditional processing steps of Mala cake are complicated and time-consuming, with low yield rate and unstable quality. However, the production of Mala cake using pre-mixed powder could effectively reduce the processing steps and maintain the product quality. The effect of fermentation time (0~70 min) on the pH value, volume growth, bubble distribution, and viscosity were determined. And the effect of different steaming intensity (5~25 mL/min) on central temperature, specific volume, water content, texture, stomatal distribution, and sensory quality of final product was also measured. The results showed that the viscosity of batter with 20%, 25%, and 30% water content firstly increased and then decreased with the extension of fermentation time, reaching the maximum viscosity at 60, 40 and 30 min, respectively. There was no significant difference (P>0.05) in the pH value and cake volume between batter with 20% and 25% water content. The pH of batter with 30% water content decreased slowly. After 70 min of fermentation, the volume increment (70.4 mL) was only 57% of the two former batters' volume increment (123.9 mL). The diameter of bubbles inside batter increased, but the number of bubbles per unit area decreased by 15%~20%, and the surface occupancy of bubbles did not change significantly. The size distribution of bubbles in batter with 25% water content was the highest. At the steaming stage, the specific volume of Mala cake was the highest at the steaming intensity of 10 mL/min, and the moisture content was the highest at the steaming intensity of 20 mL/min. When the steaming strength was lower than 15 mL/min, the hardness, elasticity, chewiness, and resilience were significantly increased with the increasing steaming strength (P<0.05). However, the texture index showed no significant (P>0.05) changes when the steaming intensity increased over 15 mL/min. Under the steam intensity of 20 mL/min, the final products showed higher elasticity and chewiness, and the internal pores were more uniform. Considering the fermentation speed, the rheological property of batter, the sensory evaluation, and texture of final products, and from the perspective of energy conservation, a better product quality could be obtained by fermenting the pre-mixed Mala cake batter with 25% water content for 40 min and then steaming at a steaming intensity of 20 mL/min.