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Title: | 以果膠酯酶催化轉醯基反應之果膠製造低糖果醬之研究 Use of pectin methyl esterase-catalyzed transacylated pectin in the making of low-sugar jam |
Authors: | Ling-Lan Lien 連鈴嵐 |
Advisor: | 吳瑞碧 |
Keyword: | 果醬,糖含量,果膠果醬,糖含量,果膠,果膠酯酶,轉醯化反應, jam,sugar content,pectin,pectin methyl esterase,transacylation, |
Publication Year : | 2010 |
Degree: | 碩士 |
Abstract: | 果膠是許多植物細胞壁中重要的一種多醣體,也是食品工業中常見的成膠劑,廣泛地應用於生產果醬、果凍等製品。前人研究指出果膠酯酶除可降解果膠甲氧基酯鍵外,亦可催化轉醯化反應 (transacylation)可使果膠分子間產生新的非甲氧基酯鍵,使果膠的分子量變大,促進果膠溶液黏度增加。故本研究擬利用果膠酯酶催化果膠分子間之轉醯基反應,以達到降低果醬之需糖量。並在含有NaCl之模式系統下,以濁度、黏度及凝膠特性變化之偵測來探討添加PME、Ca3(PO4)2、 EDTA 及檸檬酸與否對果膠酯酶轉醯化反應之影響,及低糖果醬製作之可行性。
研究發現,PME-pectin-EDTA solution比 pectin solution有較高之黏度,此外PME-pectin solutions在添加 EDTA 或檸檬酸後,果膠溶液中金屬離子被螯合,其濁度值增加,得知此時果膠酯酶較傾向催化轉醯化反應。利用PME 修飾之果膠製作含糖 30% 之果醬,其黏度範圍相當於與柑橘果膠溶液 (未添加PME,含糖量55% ~ 60%) 及市售果醬 (含糖量58% ~ 92%)。 FT-IR 非甲氧基酯鍵之生成研究結果顯示柳橙 PME 具催化轉醯化反應之能力;利用經 PME 修飾後的果膠製作含糖量30%的低糖果醬,其黏度可達市售果醬的黏度範圍,即利用經轉醯化後的果膠製做果醬可達到低糖低熱量果醬之目的。 Transacylation between pectin molecules may increase the viscosity of pectin solution. The present study was to investigate the feasibility of using pectin methyl esterase (PME) catalyzed transacylation reaction between pectin molecules to reduce the demand of sugar in jam making. Model solutions of citrus pectin added with NaCl, with and without PME, Ca3(PO4)2, EDTA and citric acid, were prepared and incubated for the enzymatic reaction to proceed. Higher viscosity in PME-pectin-EDTA solution as compared with the pectin solution indicates the occurrence of PME-catalyzed transacylation. The turbidity readings of the PME-pectin solutions were increased after the addition of EDTA or citric acid, indicating that the chelation of metal ions promotes more transacylation than deesterification and reconfirming the occurrence of transacylation in the system. Jam prepared from PME-modified citrus pectin at 300 g L-1 sucrose content was found to be in the same range of viscosity as the jam from untreated citrus pectin at 550~600 g L-1 sucrose content and commercial fruit jams at 580~920 g L-1 sugar content. We conclude that it is technically feasible to use transacylated pectin in the making of a jam with reduced sugar content. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/46119 |
Fulltext Rights: | 有償授權 |
Appears in Collections: | 食品科技研究所 |
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ntu-99-1.pdf Restricted Access | 5.94 MB | Adobe PDF |
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