頁籤選單縮合
題名 | pH值對米澱粉流變性質及回凝之影響=Effect of pH on Rheological Property and Retrogradation of Rice Starch |
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作者 | 林素一; 王奇武; 呂政義; Lin, Su-yi; Wang, Chi-wuu; Lii, Cheng-yi; |
期刊 | 中華生質能源學會會誌 |
出版日期 | 19971200 |
卷期 | 16:3/4 民86.12 |
頁次 | 頁124-134 |
分類號 | 463.36 |
語文 | chi |
關鍵詞 | 米澱粉; 流變性; pH值; 凝膠; 回凝; Rice starch; Rheological property; pH value; Gelatinization; Retrogradation; |
中文摘要 | 本研究乃選取三種不同直鏈澱粉含量的TCN1和TC189之米澱粉為樣品,配製成25%澱粉的懸浮液,並以氫氧化鈉調整pH值,再經加熱糊化,冷卻、形成澱粉凝膠,並以5℃貯存,再以動態流變儀分析為主,示差掃瞄熱分析、x-射線繞射圖譜分析、掃瞄式電子(SEM) 顯微觀察為輔,加以探討在鹼性pH條件下米澱粉之凝膠、回凝的流變性質。結果發現在加熱過程中,米澱粉懸浮液pH愈高貯存模數 (G') 愈低,而損耗正切 (tan δ ) 愈大,澱粉凝膠強度愈弱、質地愈軟偏向黏性物質;在貯存過程中隨時間之增長、直鏈澱粉含量增加及鹼性條件pH值的下降,其米澱粉凝膠之G'逐增、tanδ遞減及張力順性(compliance) 漸降,澱粉凝膠強度漸增、質地愈硬偏向彈性物質。再由米澱粉膠的pH值之上升,其DSC熱焓差 (△ H) 下降;x-之繞射波峰2��=16.9°愈不明顯,SEM之網狀孔洞愈不密實,證實在鹼性條件下pH值愈高,抑制米澱粉膠之回凝效果愈好。另從實驗中發現tan35 δ值大小與回凝程度快慢成反比。 |
英文摘要 | Two varieties of rice starch (TCN1 and TC189)with different amylose contents were used to examine the effect of pH on the rheological properties of rice starch during retrogradation. 25% starch suspension was heated at 95 ℃ for 30 min and was stored at 5℃. The rheological properties of the gelatinized starch were investigated using a dynamic rheometer at given time intervals. Other physicochemical properties were investigated using DSC, x-ray and SEM. The gel strength and G' value of rice starch decreased as pH increased. Also, the maximum G' value of rice starch during heating decreased when the pH increased. It implied that NaOH restricted the swelling of the starch. During storage, the degree of retrogradation of the starch gel decreased as pH increased. G' value was also proportional to the degree of retrogradation of the starch gel. In addition, compliance, as examined by a creep model, was inversely proportional to the degree of retrogradation of the starch gel. The enthalpy of retrogradation decreased with the increment of pH. The peak of 2��=16.9° on the x-ray diffractogram flattened as pH increased. The pore size of the structure of starch gel shown on SEM decreased with the increment of pH value. |
本系統之摘要資訊系依該期刊論文摘要之資訊為主。