Effect of high pressure carbon dioxide on the properties of water soluble pectin in peach juice
Effect of high pressure carbon dioxide on the properties of water soluble pectin in peach juice
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DOI：
10.1016/j.foodhyd.2014.02.016
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发表时间：
2014-10
影响因子：
10.7
通讯作者：
Linyan Zhou;Yongtao Wang;Fengxia Liu;Xiufang Bi;X. Liao
中科院分区：
文献类型：
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作者：
Linyan Zhou;Yongtao Wang;Fengxia Liu;Xiufang Bi;X. Liao
为了更好地了解果胶及其在高压二氧化碳诱导桃汁沉淀形成中的作用，本研究对高压二氧化碳与果胶甲酯酶联合处理桃汁中的果胶进行了脱甲氧基化、分子量分布、ξ-电位、流变性和纳米结构的研究。HPCD对WSP的分子量分布、ξ-电位和纳米结构没有影响，但促进了去甲氧基化反应。55℃温和热处理(MHT)后，PME作用显著降低了WSP的甲氧基化度(DM)和表观粘度，且WSP的纳米结构图像显示出比对照和HPCD单独的更多的聚集。缓冲体系中的PME对HPCD敏感，果汁中的PME很难被HPCD灭活。推测经HPCD处理后，桃汁中果胶的性质和结构会因PME的作用而发生明显的变化。HPCD处理后的桃汁中的WSP在PME的催化下发生脱甲氧基化反应，降低了WSP的表观粘度，导致WSP的聚集，最终加速了桃汁中沉淀的形成。
To better understand the pectin and its role in precipitation formation in peach juice induced by high pressure carbon dioxide (HPCD) in a previous study, demethoxylation, molecular weight distribution (MWD),ξ-potential, rheological properties and nanostructure of water soluble pectin (WSP) from peach juice treated by combining HPCD with pectin methylesterase (PME) were studied. The MWD,ξ-potential and nanostructure of WSP were not changed, whereas demethoxylation reaction was stimulated by HPCD. Significant decreases in degree of methoxylation (DM) and apparent viscosity of WSP were obtained with PME action after moderate heat treatment (MHT) at 55 °C, and the nanostructure image of WSP exhibited more aggregation than control and HPCD alone. PME in buffer system was susceptible to HPCD, whereas it in juice was difficult to be inactivated by HPCD. It was deduced that the properties and structure of pectin could be significantly changed with PME action in peach juice after HPCD. The apparent viscosity of WSP in peach juice could be decreased due to demethoxylation reaction catalyzed by PME in HPCD-treated juice, resulting in the aggregation of WSP, and finally contributing to accelerate the formation of precipitation in peach juice.