Interactions of pectins with cellulose during its synthesis in the absence of calcium
Interactions of pectins with cellulose during its synthesis in the absence of calcium
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DOI：
10.1016/j.foodhyd.2015.06.004
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发表时间：
2016-01-01
影响因子：
10.7
通讯作者：
Gidley, Michael J.
中科院分区：
文献类型：
--
作者：
Lin, Dehui;Lopez-Sanchez, Patricia;Gidley, Michael J.
果胶是植物细胞壁中的主要多糖成分，在植物的发育和生长中起着多种作用。为了解果胶与纤维素的相互作用，以不同中性糖侧链含量和主链同半乳糖醛酸酯化度的果胶为材料，研究了木葡糖酸醋杆菌（ATCC 53524）合成纤维素过程中果胶与纤维素的相互作用。在不存在钙的情况下进行的结合研究表明，所有类型的果胶都能够与纤维素结合，并证实具有高含量中性糖侧链（类似于40%）的果胶的结合大于同型半乳糖醛酸聚糖（小于7%中性糖）的结合。C-13 NMR显示，相关的果胶分子既不刚性，也不影响纤维素结晶度;此外，在扫描电子显微镜下观察到纤维素结构没有明显的变化。结合是可逆的，作为水洗的结果，脱粘行为主要是由表面渗透性，而不是扩散内的表膜，如模型拟合所建议的。复合材料的不可逆变形发生的机械压缩伴随着果胶的释放，我们的研究结果表明，纤维素和果胶有助于复合材料的承载能力在压缩过程中。(C)2015爱思唯尔有限公司版权所有。
Pectins are major polysaccharide components in plant cell walls and play various roles in plant development and growth. In order to understand how pectin associates with cellulose, different kinds of pectins varying in neutral sugar side-chain content and backbone homogalacturonan degree of esterification were used to study their interaction with cellulose during its synthesis by Gluconacetobacter xylinus (ATCC53524). Binding studies in the absence of calcium revealed that all types of pectin were able to bind to cellulose and confirmed that binding of pectin with a high content of neutral sugar side chains (similar to 40%) was greater than that of homogalacturonan (less than 7% neutral sugars). C-13 NMR revealed that associated pectin molecules were neither rigid nor affected cellulose crystallinity; furthermore no apparent change in cellulose architecture was observed in scanning electron micrographs. The binding was reversible as a result of water washing and the de-binding behaviour was dominated by surface permeability rather than diffusion within the pellicle, as suggested by model fitting. Irreversible deformation of composites occurred as a result of mechanical compression accompanied by the release of pectins, and our results showed that both cellulose and pectin contributed to the load-bearing capacity of composites during compression. (C) 2015 Elsevier Ltd. All rights reserved.