- 學位論文
利用α-澱粉酶延緩客家粄條老化
Utilization of α-amylase for delaying starch retrogradation of Hakka flat rice noodles
摘要
自古以來，傳統亞洲社會以米食為主食，直到現今社會依然不例外，以米為主軸而延伸出的食品族繁不及備載，造就出深遠的米食文化歷史。台灣有閩南和客家人，閩南人傳統米食如湯圓、肉粽聞名，客家人以粄，或者稱粄條聞名。米食常見的問題就是澱粉老化，所以米食的儲存和加工條件顯得特別重要。本研究主要目的是探討如何延緩客家粄條的澱粉老化，使用的方法是利用不同濃度的α-澱粉酶(α-amylase)處理在來米粉製成粄條，並研究是否能減緩老化現象，藉由物理分析、化學分析及感官品評評估澱粉老化的變化，其中物理方法有物理結構分析、水活性分析、水分含量分析、色差儀分析，而化學分析則利用酵素分析法。相同儲存時間下，未加酵素的粄條相對於有加酵素的粄條，未加酵素的粄條分析出硬度有最明顯的上升變化，水分含量變化下降最多，澱粉水解率下降幅度較大；而添加10 mg/kg和20 mg/kg酵素濃度的粄條相比，添加20 mg/kg酵素濃度的粄條水分含量和水活性較10 mg/kg低，且澱粉水解率比10 mg/kg低，代表著澱粉老化程度也較高，此外在感官品評分析上，品評人員較能接受添加酵素的粄條樣品，因此從上述分析結果得知10 mg/kg酵素濃度是作為延緩澱粉老化的最佳濃度。
並列摘要
Traditional Asian society regards rice foods as staple food down the ages, nowadays society also do. Many kinds of rice foods extend from rice, it contributes to far-reaching rice foods cultural history. There are two ethnic groups in Taiwanese society. Minnan people are famous for sticky rice dumplings and rice dumplings. Hakka are famous for Hakka flat rice noodles. Starch retrogradation appearance is a common problem in the rice foods, so rice foods storage and process conditions are obviously important. The purpose of the research is in order to postpone starch retrogradation phenomenon of Hakka flat rice noodles. The method is utilize different concentration of α-amylase into indica rice powder and produce Hakka flat rice noodles to slow down starch retrogradation. By means of physical, chemical tests and sensory evaluation analysis the variation of starch retrogradation. The physical tests contain texture profile analysis, water activity, moisture content, colour measurement. The chemical test is enzyme analysis. None enzyme treatment Hakka flat rice noodles compare with enzyme treatment Hakka flat rice noodles during same storage time, none enzyme treatment Hakka flat rice noodles had clear hardness variation, moisture content decreased the most variation, and starch digestibility variation had more decline. 10 mg/kg enzyme treatment Hakka flat rice noodles compare with 20 mg/kg ones, 20 mg/kg enzyme treatment Hakka flat rice noodles had lower water activity than 10 mg/kg ones, and it had lower starch digestibility, represent 20 mg/kg enzyme treatment Hakka flat rice noodles had stronger starch retrogradation phenomenon. In addition, in the sensory evaluation analysis, the evaluation staff is more able to accept the sample of the Hakka flat rice noodles with enzyme added. Hence, from the above analysis results, the enzyme concentration of 10 mg/kg is the best concentration to delay starch retrogradation.