學生姓名:
盛美麗
指導教授:
宋文杰
學 期:
114上
摘 要:
The retrogradation phenomenon of starch is mainly a primary challenge in the production of rice cake (RC) as it is causing a rapid decrease in quality and reduces shelf-life period of the RC that leads to consumer acceptability decrease. This report compares the retrogradation retarding mechanisms of maltogenic α-amylase (MA), glycerol (GLY), and sucrose stearate (sucrose fatty acid ester; SE). MA was incorporated into the RC with concentration ranging from 1.5×10-3 U/g to 9.5×10-3 U/g in the rice flour. The optimal concentration was concluded in 4.0×10-3 U/g after account the sensory acceptability test. Long amylopectin chains were hydrolyzed by MA into shorter fragments (DP ≤ 9) and leads to gelatinization enthalpy decrease, reduced setback viscosity, and maintaining the RC softness during the 7-days storage period at 4˚C. When GLY (1%, 5%, and 10%) and SE (0.1%, 0.3%, and 0.5%) were added to the RC, the most pronounced inhibition observed at 5% GLY and 0.3-0.5% SE. GLY weakened the hydrogen bonding and delayed recrystallization, while SE formed starch-lipid complexes that were obvious with the Vtype crystal pattern that hindered the recrystallization of starch molecules. Both additives show the decrease in initial hardness and reduced amylopectin melting enthalpy. Overall, these agents were working with different mechanics in the molecular level and giving positive results of retard the retrogradation process success. It is also evident that the changes in the physical attribute are not always concurrent with the definition of retrogradation in the molecular level
盛美麗.pdf