The Study On Quality Evaluation And Process Technology Of Rice Steamed Sponge Cake

Rice steamed sponge cake was a distinct ethnic traditional food, very popular in southern China area, which is made from long rice by soaking, grinding, fermentation and steaming, formed a cake with honeycomb structure, soft texture, pleasant fermented flavor, easy to digestion and absorption. However, it has maintained the traditional manual production, without the guidance of scientific theory, lacked of standards in process control, which lead to unstable quality, small production, far away from the level of industrialization and modernization. Using modern food technology to explore, organize, scientifically improve and develop the Chinese traditional food can advance the level of the Chinese diet and promote the oriental culture.The main contents and results as follows:1. Systematically studied establishment of sensory evaluation system for rice steamed sponge cake quality. Based on the fuzzy binary contrast a special expertise investigation was done and selected out 12 items of sensory quality parameter for evaluating the quality of rice steamed sponge cake. And then by means of the other expertise investigation and derived statistics methods, the weight coefficients of every quality parameters for quality evaluation of rice steamed sponge cake were obtained. Furthermore, the quality evaluation system was established respectively for rice steamed sponge cake.2. The correlation between sensory evaluation and texture properties were studied. Hardness and gumminess were significant negative correlative, resilience and cohesiveness were significant positive correlative. Chewiness is a comprehensive characterization of the quality. Hardness was significantly negatively correlated to sensory score, and springness positively correlated, both of them could be preferential texture properties.3. The effect of steaming process on textural characteristics of steamed sponge rice cake was evaluated by response surface methodology (RSM) with different pressure-time combination. The adequacy of the model for predicting the optimum response values was verified. The results showed that hardness was suitable under the steaming pressure 101 kPa or steaming treatment 121 kPa, 15min. Gumminess reached the minimum value and resilience, cohesiveness reached the maximum at 101 kPa, 15 min. Springness was only negative correlation to pressure. Chewiness was suitable under 5 min, 121 kPa or 25 min, 101 kPa. Considering all the textural characteristics, the optimum steaming treatment pressure is lOlkPa and the processing time is 15min. By the mathematical models, a better regulation on steaming process can be obtained which was a very important base of the industrialization of rice steamed sponge cake.4. The characteristics of 10 rice raw materials and the texture properties of rice steamed sponge cake were studied, and the relationships between them were discussed. As a result, the standard of rice for rice steamed sponge cake was established. Results showed that the content of amylase, breakdown and setback of rice could be regarded as the major indexes for the standard of rice for rice steamed sponge cake. Among these three indexes, the content of amylase had the greatest contribution to the quality of rice steamed sponge cake. There was significant positive correlation between the content of amylase and hardness, resilience and chewiness.5. By studying the chemical composition changes of rice before and after fermentation, found purification of starch is one of the most important role of fermentation. And it improved the starch gelatinization properties and rheological properties, so as to improved the quality of rice steamed sponge cake. Fermentation did not change the structure and starch grain type of rice.