Effects of carrageenan type on the behaviour of carrageenan/milk mixtures
Effects of carrageenan type on the behaviour of carrageenan/milk mixtures
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DOI：
10.1016/s0268-005x(99)00064-8
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发表时间：
2000-07-01
影响因子：
10.7
通讯作者：
De kruif, CG
中科院分区：
文献类型：
--
作者：
Langendorff, V;Cuvelier, G;De kruif, CG
酪蛋白胶束的表观流体动力学直径被确定为在60 ℃和冷却至20 ℃期间的水胶体浓度的函数。所研究的系统含有脱脂乳100倍稀释的渗透物中的存在下，无论是λ-，iota-，κ-角叉菜胶或瓜尔胶。这些测量结果表明，所有三种形式的卡拉胶吸附到酪蛋白胶束，而瓜尔胶不。λ-角叉菜胶（始终处于螺旋构象）在所有研究的温度下吸附，而iota和kappa形式仅在低于螺旋-螺旋转变开始的温度下吸附。结果同意的想法，吸附的卡拉胶只发生在一定的最小电荷密度以上。在60 ℃下建立三种角叉菜胶的相图，并在冷却和25 ℃下跟踪流变行为。结果表明，在低卡拉胶浓度下，卡拉胶-卡拉胶桥接酪蛋白胶束，导致卡拉胶/牛奶混合物在60 ℃下沉降，并在冷却时形成结构。在60 ° C下，i-和K-角叉菜胶诱导高于临界角叉菜胶浓度的酪蛋白胶束的消耗絮凝。在冷却时，含有ι-角叉菜胶的系统在螺旋-卷曲转变温度下明显形成网络。该网络由混合的角叉菜胶/酪蛋白胶束交联形成。在存在过量角叉菜胶的情况下，该网络通过角叉菜胶/角叉菜胶交联而增强。对于κ-卡拉胶/酪蛋白胶束混合物，混合卡拉胶/酪蛋白胶束交联的存在不太明显，但似乎是可能的。(C)2000爱思唯尔科技有限公司版权所有。
The apparent hydrodynamic diameter of casein micelles was determined as a function of hydrocolloid concentration at 60 degrees C and during cooling to 20 degrees C. The systems studied contained skim milk 100-fold diluted in permeate in the presence of either lambda-, iota-, kappa-carrageenan or guar gum. These measurements show that all three forms of carrageenan adsorb onto casein micelles, whereas guar gum does not. Lambda-carrageenan (which is always in the coil conformation) adsorbs at all the temperatures studied, whereas the iota and kappa forms adsorb only at temperatures below the onset of the helix-coil transition. The results agree with the idea that adsorption of carrageenan occurs only above a certain minimum charge density. Phase diagrams were established at 60 degrees C for the three carrageenans and the rheological behaviour was followed on cooling and at 25 degrees C. The results suggest that the lambda-carrageenan bridges the casein micelles at low carrageenan concentrations, leading to the sedimentation of carrageenan/milk mixtures at 60 degrees C and structure formation on cooling. At 60 degrees C, iota- and kappa-carrageenan induce depletion flocculation of casein micelles above a critical carrageenan concentration. On cooling, systems containing iota-carrageenan clearly form a network at the helix-coil transition temperature. The network is formed by mixed carrageenan/casein micelle crosslinks. In the presence of excess carrageenan, this network is reinforced by carrageenan/carrageenan crosslinks. For the kappa-carrageenan/casein micelle mixtures the existence of mixed carrageenan/casein micelle crosslinks is less obvious but seems likely. (C) 2000 Elsevier Science Ltd. All rights reserved.