PRODUCTION OF A LOW ESTER PECTIN BY DE – ESTERIFICATION OF HIGH ESTER CITRUS PECTIN
PRODUCTION OF A LOW ESTER PECTIN BY DE – ESTERIFICATION OF HIGH ESTER CITRUS PECTIN
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DOI：
10.1016/0144-8617(95)00051-8
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发表时间：
1995
影响因子：
11.2
通讯作者：
S. A. El-Nawawi;Y. Heikal
中科院分区：
文献类型：
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作者：
S. A. El-Nawawi;Y. Heikal
研究了高酯柑橘果胶在盐酸水溶液和异丙醇混合氨处理下的脱酯化动力学，考察了甲酯基、分子量和酸性酰胺基形成的变化。用HCl进行酸去甲基化反应表明，在较低的温度和较低的浓度下，较高浓度的酸在脱酯化过程中的解聚作用要小于较低浓度的酸。在不同温度、不同氨水浓度的一系列NH4OH脱酯化和酰胺化反应中，随着温度的降低和氨水浓度的增加，表观分子量保持得较好，酯基有所减少。
The kinetics of de-esterification of high ester citrus pectin, using aqueous hydrochloric acid (HCl) solution or treatment with a mixture of ammonia in isopropanol were studied with respect to changes in methyl ester groups, molecular weight, and the formation of acid amide groups. Acid demethylation using HCl showed that higher concentrations of acid at low temperatures gave less depolymerization during de-esterification than when lower concentrations and higher temperatures were used. In a series of NH4OH de-esterifications and amidations using different ammonia concentrations at different temperatures, apparent molecular weight was retained better with a certain decrease of ester groups, as the temperature was lowered and the concentration of ammonia increased.