Fractionation of starch hydrolysate into dextrin fractions with low dispersity by gradient alcohol precipitation
Fractionation of starch hydrolysate into dextrin fractions with low dispersity by gradient alcohol precipitation
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DOI：
10.1016/j.seppur.2015.07.044
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发表时间：
2015-09-04
影响因子：
8.6
通讯作者：
Tian, Yaoqi
中科院分区：
文献类型：
--
作者：
Hu, Xiuting;Liu, Chengmei;Tian, Yaoqi
建立了梯度醇沉分馏方法，将1-丁醇- hc1水解木薯淀粉分馏成分子量分布较窄的糊精馏分。添加酒精可能会导致糊精溶液中某些部分的酒精浓度非常高，这可能会阻碍分馏过程。因此，在分馏过程中应严格控制醇的添加速率。以分子量分散度（D-M）为指标，研究了醇型和初始糊精浓度对分馏的影响。采用梯度醇沉法将母体糊精分馏成7个组分，糊精溶液与醇的体积比分别为4:1、2:1、1:1、1:2、1:3、1:4、1:5，D-M依次递减。不同醇类的分馏效果较好的依次为甲醇b>乙醇b>异丙醇；而这些醇的糊精产率却是相反的。此外，随着醇浓度的增加，各馏分的峰值分子量有降低的趋势。最佳初始浓度为1.8% ~ 2.7%，浓度越低越好，分馏效果越差。这些结果表明，梯度醇沉淀法是一种有效的方法，可以将糊精分离成具有不同低D-M摩尔质量的馏分，这将使糊精馏分适合特定的应用。Elsevier B.V.版权所有
Gradient alcohol precipitation was established as a fractionation method, and used for fractionating the 1-butanol-HC1-hydrolyzed cassava starch into dextrin fractions with a narrower molecular weight distribution. The addition of alcohol may have led to very high alcohol concentration in some parts of the dextrin solution, which may have impeded the fractionation process. Therefore, the rate of alcohol addition should be rigorously controlled during fractionation. The effects of the alcohol type and the initial dextrin concentration on fractionation were studied using the molecular-weight dispersity (D-M) as index. The parent dextrin was fractionated by gradient alcohol precipitation into seven fractions with decreasing D-M, with the volume ratios of the dextrin solution to alcohol at 4:1, 2:1, 1:1, 1:2, 1:3, 1:4, and 1:5, respectively. The better fractionation effect of different alcohols was in the order of methanol > ethanol > isopropanol; whereas the dextrin yield by these alcohols was in the reverse order. Furthermore, the peak molecular weight of each fraction tended to decrease with an increase in the alcohol concentration at which it was precipitated. The optimal initial concentration was in the range of 1.8%-2.7%, and lower or higher concentrations resulted in inferior fractionation. These results suggest that gradient alcohol precipitation is an efficient method for fractionating dextrin into fractions with different molar masses of low D-M, which would allow dextrin fractions to be tailor-made for specific application. Crown Copyright (C) 2015 Published by Elsevier B.V. All rights reserved.