Mixed Gels Formed with Konjac Mannan and Xanthan Gum
Mixed Gels Formed with Konjac Mannan and Xanthan Gum
复制标题
魔芋甘露聚糖和黄原胶形成的混合凝胶
DOI：
10.1533/9781845698331.339
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发表时间：
1991
期刊：
影响因子：
2.9
通讯作者：
K. Nishinari
中科院分区：
文献类型：
--
作者：
P. Williams;S. Clegg;D. Day;G. Phillips;K. Nishinari
出版商摘要魔芋甘露聚糖(KM)是一种β-D-(1-4)连接的葡甘聚糖，含有1-3个连接在C-3的葡萄糖和甘露糖残基。天然KM可溶于水，而脱乙酰基可形成热不可逆凝胶。黄原胶具有β-D-(L-4)连接的葡聚糖骨架，在交替的葡萄糖残基上含有由α-D-甘露糖、β-D-葡萄糖醛酸和β-D-甘露糖组成的短三糖侧链。黄原胶在水溶液中不会形成真正的凝胶，但它已被证明经历了一种热诱导的构象变化，这种变化对电解液的存在很敏感。据报道，黄原胶+KM的混合物可以形成热可逆的凝胶，所产生的凝胶比黄原胶和半乳甘露聚糖形成的凝胶更坚固，熔点更高。早期的工作表明，在有序的黄原胶分子和半乳甘露聚糖或葡甘聚糖链之间发生了特定的相互作用。M.Tako总结说，黄原胶侧链和半乳甘露聚糖主链之间存在分子间相互作用，分子采用与固体相同的有序构象。G.J.Brownsey认为，分子间结合涉及无序的黄原链的部分与结构相似的半乳甘露聚糖链或葡甘聚糖链的部分共结晶。这一章的目的是提供黄原胶和KM分子间结合的进一步证据，并进一步阐明凝胶机理。结果表明，KM与黄原胶分子以两种不同构象相互作用。
Publisher Summary Konjac Mannan (KM) is a β-D-(1-4) linked glucomannan and contains 1-3 linked branches occurring at C-3 of glucose and mannose residues. Whereas native KM is soluble in water, deacetylation results in the formation of a thermally irreversible gel. Xanthan gum has a β-D-(l-4) linked glucan backbone with short trisaccharide side-chains consisting of α-D-mannose, β-D-glucuronic acid, and β-D-mannose on alternating glucose residues. Xanthan gum does not form true gels in aqueous solution but it has been shown to undergo a thermally induced conformational change that is sensitive to the presence of electrolyte. Mixtures of xanthan + KM have been reported to form thermally reversible gels and the gels produced are much stronger and have higher melting points than those formed between xanthan and galactomannans. Early work suggested that a specific interaction occurred between the ordered xanthan molecule and the galactomannan or glucomannan chain. M. Tako concluded that intermolecular interaction occurs between the xanthan side chains and the galactomannan backbone and that the molecules adopt the same ordered conformation as in the solid state. G. J. Brownsey suggested that intermolecular binding involves co-crystallization of sections of the disordered xanthan chain with the structurally similar segments of the galactomannan or glucomannan chain. This chapter presents a paper with the purpose to providing further evidence of intermolecular binding between xanthan and KM and to shed further light on the gelation mechanism. It is concluded that KM interacts with xanthan molecules in two different conformational forms.