以國產富機能性有色米穀粉開發新穎式中式麵條

Abstract

本研究選用國產有色米（花蓮太巴塱紅糯米(RW)與花蓮太巴塱黑糯米(BW)）為試驗材料，分析其理化性質及機能性成分，並探討濕熱處理對有色米理化性質之影響。試驗中，以30%及51%有色米穀粉（未處理及濕熱處理）取代小麥麵粉，建立製程，製備富含機能成分之中式米麵條，並探討取代程度及濕熱處理米穀粉，對有色米麵條的烹煮品質與質地之影響。此外，將米麵條預拌粉（米穀粉：小麥粉=3:7及51:49），進行90天貯藏試驗，分析其於貯藏期間，機能性成分與游離脂肪酸含量變化。實驗結果發現，紅糯米與黑糯米經濕熱處理後，澱粉分子內部發生重排，因此糊化溫度提高。且濕熱處理15 分鐘以上，可使米穀粉中酵素活性失活，造成黏度分析中，最高黏度與最終黏度上升。此外，以稻穀形式進行濕熱處理，可降低濕熱處理中熱與水分對其糊液黏度性質之影響程度。熱性質分析結果顯示，濕熱處理將造成吸熱峰往高溫移動，並使熱焓值減少。濕熱處理時糊化情形隨加水量之增加漸趨明顯，且水分對糊化程度的影響較時間更為顯著。以濕熱處理15分鐘之米穀粉和小麥麵粉30%或51%進行配粉，其糊液黏度特性與純小麥麵粉最為接近，故以此配粉製作米麵條。米麵條中，以稻穀形式濕熱處理15分鐘之米穀粉製作米麵條，麵糰成糰性較佳，與小麥麵條之外觀亦較為相近。麵條性質與質地測定結果中發現，以米穀粉取代之米麵條，烹煮時間顯著減少；以稻穀形式濕熱處理15分鐘後，其米麵條烹煮損失率最低，並具有較低的黏著力與較大的拉伸性。以51%米穀粉取代之米麵條，添加活性麵筋可使米麵條之烹煮損失率與黏著力下降，並提升其硬度、咀嚼性與柔軟度。添加8.8%活性麵筋可維持熟麵條之完整性，增強麵條結構。官能品評結果顯示，51%米穀粉取代之紅糯及黑糯米麵條之接受度較30%取代之米麵條為高。濕熱處理15分鐘之紅糯米穀粉所製備之51%取代米麵條，其整體接受度在紅米麵條中最佳。以濕熱處理15分鐘之紅糯米穀粉，和以未經處理之黑糯米穀粉或濕熱處理15分鐘之黑糯米穀粉，添加8.8%之活性麵筋，所製備之51%取代米麵條，最具開發潛力。貯藏試驗中，濕熱處理會抑制酵素活性；而4 oC貯藏則可降低游離脂肪酸含量。機能性成分測定中，黑糯米麵條總酚含量為紅糯米麵條之兩倍。黑糯米穀粉總花青素含量不受貯藏溫度之影響。製成黑糯米麵條後，總花青素含量仍維持原料之70%。本研究成果不僅提升國產有色米應用範疇，更提供國人富機能性新穎米食製品之新選擇。

The physical properties and bioactive compounds of domestic colored rice (RW and BW) were investigated. Furthermore, the effects of heat-moisture treatment (hmt) of the colored rice on the physical properties were investigated. The process of 30% and 51% substitution of colored rice (including hmt rice) with wheat flour for bioactive Chinese rice noodle making was built up. The effect of rice replacement levels and hmt levels on cooking quality and textural properties of colored rice noodles were also investigated. The mixture of rice flour and wheat (rice flour: wheat = 3:7 and 51:49) was stored for 90 days to evaluate the changes of free fatty acids and bioactive compounds during storage. The pasting properties analysis results showed that the hmt rice flour had higher pasting temperature due to molecular rearrangement of starch molecules. When hmt time is over 15 min, it inactivated enzyme, and caused peak and final viscosity increased. When the heat-moisture treatment was processed in rough rice form, the effect of heat and moisture to pasting properties was reduced. The thermal properties analysis results showed that hmt caused TO shifted to higher values and enthalpy reduced. The additional moisture during hmt caused higher gelatinization level, and the effect of moisture to gelatinization level was more obvious than heating time to it. The mixture of wheat and hmt rice (30% and 51%) showed a pasting viscosity similar to pure wheat flour and may ideally substitute for wheat flour in noodle preparation. Rice noodle had less cooking time than wheat noodle. The rice noodle containing hmt in rough rice form had lower cooking loss and adhesiveness, and higher tensile strength than noodle containing untreated rice. Adding 8.8% vital gluten in 51% substitution rice noodles decreased cooking loss and adhesiveness, and also increased firmness, chewiness and tenderness. The sensory evaluation results showed that the 51% substitution rice noodle had the higher value on total acceptance. The 51 % substitution hmt (15 min) red rice noodle had the highest value of total acceptance in red rice noodle. 51% rice noodle prepared from hmt red rice, native or hmt black rice showed the beat potential to rice noodle products. During storage, the lower storage temperature at 4 oC and hmt caused less free fatty acid. In bioactive compounds analysis, total phenolics in black rice noodle was two times of red rice noodle. Total anthocyanins in black rice was not affected by storage temperature. There was 70% maintenance in total anthocyanins from black rice flour to black noodles. The results of this study not only promote the application category in domestic colored rice but also provide new choice about bioactive novel rice products for compatriots.