頁籤選單縮合
題 名 | 以熱機械分析法探討多元醇及食鹽對米澱粉、米穀粉與米澱粉凝膠之影響=Effects of Polyols and NaCl on Rice Starch, Flour, and Starch Gel by TMA |
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作 者 | 黃瑞美; 葉貞吟; 呂政義; | 書刊名 | 中國農業化學會誌 |
卷 期 | 35:1 1997.02[民86.02] |
頁 次 | 頁86-95 |
分類號 | 463.36 |
關鍵詞 | 熱機械分析; 多元醇; 米澱粉; 米穀粉; 澱粉凝膠; TMA; Polyol; Rice starch; Rice flour; Starch gel; |
語 文 | 中文(Chinese) |
中文摘要 | 選用三種米澱粉、米穀粉與米澱粉凝膠(秈、�牷B糯),藉熱機械分析法( thermomechanical analysis) 分別測試其 Tg, 並探討多元醇 (polyols) 及食鹽 (NaCl) 等添加物對它之影響。結果以體積膨脹法測試,發現糯米澱粉之體積會呈一段式急速膨脹, 而非糯性米澱粉則呈二段漸進式膨脹。45~50% (w/w) 米澱粉之 Tg 約在 60~70 ℃,且糯米 澱粉較高。如以共溶劑 (Cosolvent) 方式,將 40% 多元醇加到 35~45% 之米澱粉中,結果 Tg 會顯著提高至 76~93 ℃, 尤其是果寡醣 (fructooligosaccharide) 與麥芽糊精 (maltodextrin); 即多元醇具塑化效果,其塑化趨勢為單糖 > 雙糖 > 寡醣 > 多醣 >,亦 即多元醇平均分子量愈小,塑化效果愈大。以同法將 10% NaCl 加到 45~50% 之米澱粉中, 結果 Tg 亦會提高至 69~82 ℃。 至於米穀粉方面,添加多元醇及食鹽,其體積膨脹變化趨 勢與米澱粉均相同。另以穿刺法探測 40% �狾抩�粉凝膠系統,其 Tg' 約在 -5 ℃,添加多 元醇及食鹽其 Tg' 均會降低,且多元醇濃度愈高或平均分子量愈小,Tg' 下降量亦愈大。 |
英文摘要 | The Tgs of three varieties of rice (i.e., indica, japonica, and waxy) starches, flours and starch gels as well as the effects of polyols and NaCl additivies on the Tg were investigated through thermomechanical analysis (TMA). The results indicated that the volume expansion of waxy rice starch increased drastically in a single stage, and that the volume expansion of the nonwaxy starch increased slowly in two stages when examined by using the volume expansion method. The Tgs of 45~50% starch (w/w) ragned from 60 to 70 ℃, and the waxy variety showed higher Tg. When the 40% of polyols was added with the cosolvent system to 35~45% starch, the Tgs rose to 76~93 ℃, expecially for fructooligosaccharide and maltodextrin. This implied that the polyol carried the plasticizing effect. The degree of the plasticizing effect for the polyols was in the following order: monosaccharide > disaccharide > oligosaccharide > polysaccharide. This suggested that the plasticizing effect was inversely proportional to the molecular weight of the polyol. The Tgs of the 45~50% starch with addition of 10% NaCl increased tod 69~82 ℃. The volume expansion at Tg and the influence of the addition of polyols and NaCl on the rice flours were similar to those of the rice starches. The Tg' of the 40% japonica rice starch gel was about -5 ℃ as found from the penetration test. The addition of polyol and NaCl decreased Tg'. Tg' decreased with the increment of the concentration and the decrease of the average molecular weight of the additive. |
本系統中英文摘要資訊取自各篇刊載內容。