αs-Casein-PE6400 mixtures: Surface properties, miscibility and self-assembly
αs-Casein-PE6400 mixtures: Surface properties, miscibility and self-assembly
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DOI：
10.1016/j.colsurfb.2014.03.030
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发表时间：
2014-06-01
影响因子：
5.8
通讯作者：
Weiss, Jochen
中科院分区：
文献类型：
--
作者：
Kessler, Anne;Menendez-Aguirre, Orquidea;Weiss, Jochen
研究了食品级酪蛋白与三嵌段共聚物PE 6400（PEO 13-PPO 30-PEO 13）的混合物的表面性质、溶解性和自组装性。通过测量1：1摩尔混合物的表面压力来确定表面处的性质。的测量与计算的等温线的比较显示在9 mN/m以上的表面压力的吸引力的相互作用。考察了含0.004- 0.2mmol/l α-酪蛋白和0.02- 0.1mol/l聚合物溶液的溶解度间隙。有人发现，一个单相区存在于不同的混合比和温度。α（s）-酪蛋白和PE 6400的混合物与纯α（s）-酪蛋白的浊点的比较表明，三嵌段共聚物的存在增强了蛋白质的溶解度。通过添加PE 6400，α（s）-酪蛋白溶液的ζ-电位降低至零。因此，我们的研究结果表明，α（S）-酪蛋白和PE 6400是可混溶的。浊点和ζ-电位测量的结果通过混合聚集体的形成来解释，其中PPO链锚定在α（s）-酪蛋白的疏水部分内，而PEO链覆盖α（s）-酪蛋白的带电亲水部分，从而导致浊点增加和ζ-电位降低。这与通过在表面处的表面压力测量观察到的α（s）-酪蛋白和PE 6400之间的吸引相互作用一致。(C)2014爱思唯尔有限公司版权所有。
Surface properties, miscibility and self-assembly of mixtures of a food-grade as-casein and the triblock copolymer PE6400 (PEO13-PPO30-PEO13) were examined. The properties at the surface were determined by surface pressure measurements for a 1:1 molar mixture. Comparison of the measured with the calculated isotherms show attractive interactions at surface pressures above 9 mN/m. The miscibility gaps of solutions containing 0.004-0.2 mmol/l alpha(s)-casein and 0.02-0.1 mol/l polymer were examined. It was found that a one-phase region exists at distinct mixing ratios and temperatures. Comparison of the cloud points of mixtures of alpha(s)-casein and PE6400 with pure alpha(s)-casein showed that the presence of the triblock copolymer enhanced the solubility of the protein. The zeta-potential of the alpha(s)-casein solution decreased by addition of PE6400 to zero. Our results thus suggest that alpha(s)-casein and PE6400 are miscible. The results of the cloud point and zeta-potential measurements were explained by formation of a mixed aggregate where the PPO chains are anchored inside the hydrophobic part of the alpha(s)-casein while the PEO chains cover the charged hydrophilic part of the alpha(s)-casein thereby leading to an increase of the cloud point and a decrease in zeta-potential. This is in agreement with the attractive interactions between alpha(s)-casein and PE6400 as observed via surface pressure measurements at the surface. (C) 2014 Elsevier B.V. All rights reserved.