Study On Staling Chanism And Anti-Staling Of Fermented Rice Cake

Fermented rice cake is made in a process of soaking, beating, fermentation of rice and steaming. The finished product of the cake, with honeycomb structure, soft taste and joyful bouquet aroma of fermentation, is easy to be digested and assimilated by the human body. The cake integrating palatability, security and nutritiousness is a specialty food in South China; thanks to its vivid regionalism flavor and ethnic cultural characteristics, this kind of cake is popular in China. However, its production has not attracted enough attention of investigators. Currently, it is still in manual operation phase: producing for selling, a small output. Especially, its production only rooted in folk experience has no scientific theoretical guidance, which leads to instability of product quality and makes it difficult to meet the growing demand for consumption. Therefore, it is the general trend and an inevitable choice to adopt modern high-tech to improve and reconstruct feature flavor food processing industry so that the industry can realize quantification, standardization, mechanization and automatization and that the original flavor and nutrient value of the food can be preserved to the utmost.On the basis of currently widely-used food additives for rice-made products, this text aims to gain a compound food additive to ameliorate quality and postpone aging of the cake; it has also studied the aging mechanism of the cake, in the hope of finding out the influential elements. In a word, the study is performed in order to gain the cake of good quality, good repeated steaming, and long shelf life. Principal study results are as follows:1. This text has studied influences of sucrose fatty acid ester (SE), sodium stearoyl lactylate (SSL),α-amylase, xylanase, xanthan and sodium alginate as well as their compound additives on the rice cake quality. The texture analyzer test and sensory score are used for the evaluation of the rice cake quality. Conclusion:single emulsifying agent, enzyme preparation and hydrophilic colloid can ameliorate the rice cake quality; especially the compound has more conspicuous effects. The best compound proportion is: 8g/kg SE,2g/kg SSL,0.03g/kgα-amylase,0.05g/kg xylanase,2g/kg xanthan and 0.2g/kg sodium alginate. The improved cake is of ameliorated internal structure, small and even air holes, smooth taste, softness, and better resilience.2. The text has also studied and analyzed aging evaluation parameters for aging of the cake, clarifying the aging mechanism of the cake. Conclusion:with storage prolongation of the cake, its moisture content, soluble starch content and sensory score will decrease, but its hardness, thermodynamic parameter (initial temperature To, phase variation temperature Tg, phase variation terminal temperature Tc, enthalpyΔH) and crystallinity will increase accordingly. Therein, Tc is significantly correlated to soluble starch content; storage time to enthalpy; moisture content to phase variation terminal temperature and soluble starch content. After analyzing aging elements, the text expounds that the aging of the cake is a course of gelatinized starch molecules reforming new crystal structures.3. This text has further studied influences of SE and a-amylase on aging resistance of the cake. After adding SE and a-amylase respectively, the organoleptic properties (including volume, quality and specific volume, etc) and texture properties (including hardness, cohesion, resilience, adhering and mastication, etc) of the cake are analyzed. Conclusion:SE and a-amylase have certain effect on aging resistance of the cake. The best proportion is:12g/kg SE, and 0.05g/kg a-amylase. SE effect is better than that of a-amylase.