Thermal degradation of citrus pectin in low-moisture environment - Influence of acidic and alkaline pre-treatment
Thermal degradation of citrus pectin in low-moisture environment - Influence of acidic and alkaline pre-treatment
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DOI：
10.1016/j.foodhyd.2018.02.030
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发表时间：
2019-01-01
影响因子：
10.7
通讯作者：
Drusch, Stephan
中科院分区：
文献类型：
--
作者：
Einhorn-Stoll, Ulrike;Kastner, Hanna;Drusch, Stephan
果胶粉末在储存和运输过程中通过脱甲氧基和解聚而降解。降解机制，特别是预处理对降解反应的影响还没有完全了解。在这项研究中，商业柑橘果胶改性无论是酸性或碱性脱甲氧基。改性果胶以及商业果胶在60 ° C和80%相对湿度下储存四周期间热降解。脱甲氧基和解聚以及颜色的变化进行了检查，在降解过程中，和反应的过程进行了monitored.It被发现，在修改过程中的预处理的类型确定的材料特性，因此，改性果胶粉的吸水率。样品中所得的水可用性对于脱甲氧基化的程度以及解聚的类型和强度至关重要，因为这些反应中的一些竞争气候室中的水。预处理还测定了改性果胶的中性糖和钠离子含量。这些组分的高含量以不同方式限制了果胶的降解程度，证实了除主链水解和β-消除外，果胶的第三种解聚机理。(C)2018爱思唯尔有限公司版权所有。
Pectin powder is degraded during storage and transport by demethoxylation and depolymerisation. The degradation mechanisms and especially the influence of pre-treatments on the degradation reactions are not completely understood. In this study, commercial citrus pectin was modified by either acidic or alkaline demethoxylation. The modified pectins, as well as the commercial pectin, were thermally degraded during four weeks of storage at 60 degrees C and 80% relative humidity. Demethoxylation and depolymerisation as well as colour alterations were examined during degradation, and the course of the reactions was monitored.It was found that the type of pre-treatment during modification determined the material properties and, thus, the water uptake of the modified pectin powders. The resulting water availability in the samples was crucial to the extent of demethoxylation and to the type and intensity of depolymerisation since some of these reactions competed for the water in the climate chamber. The pre-treatment also determined the content of neutral sugars and sodium ions of the modified pectins. High contents of these components limited the extent of degradation in different ways.A previously assumed third depolymerisation mechanism of pectins, beside backbone hydrolysis and beta-elimination, was confirmed. (C) 2018 Elsevier Ltd. All rights reserved.