de Vries Auke, Wesseling Anne, van der Linden Erik, Scholten Elke
Top Institute Food and Nutrition, Nieuwe Kanaal 9A, 6709 PA Wageningen, The Netherlands; Wageningen University, Laboratory of Physics and Physical Chemistry of Foods, P.O. Box 17, 6700 AA Wageningen, The Netherlands.
Wageningen University, Laboratory of Physics and Physical Chemistry of Foods, P.O. Box 17, 6700 AA Wageningen, The Netherlands.
J Colloid Interface Sci. 2017 Jan 15;486:75-83. doi: 10.1016/j.jcis.2016.09.043. Epub 2016 Sep 21.
In this research we use heat-set whey protein aggregates (diameter∼200nm) as novel building blocks for structure formation in liquid oil to form oleogels. To transfer the aggregates to the oil phase, a solvent exchange procedure to sunflower oil was applied using acetone as an intermediate solvent. We found that agglomeration of the aggregates was prevented and the particle size in oil did not change from that in the initial aqueous phase. The small protein aggregates assemble into a space-spanning network, thereby providing solid-like properties to liquid oil. From oscillatory rheology we conclude that the aggregates are highly effective in forming a network. Already at ∼3% we found that G'>G″ and G' scales with protein concentration as G'∼c. Applying a fractal gel network theory to the rheological data we deduce that the gels are in the strong link regime with a fractal dimension of 2.2. The results show that protein aggregates, besides their well-known functionality in aqueous solvents, are capable of forming a network in liquid oil. This provides a novel and promising way to design oleogels with tuneable rheological properties, applicable to e.g. foods, pharmaceuticals and/or cosmetics.
在本研究中，我们使用热凝乳清蛋白聚集体（直径约200nm）作为新型构建单元，用于在液态油中形成结构以制备油凝胶。为了将聚集体转移至油相，采用丙酮作为中间溶剂，通过溶剂交换程序将其转移至葵花籽油中。我们发现聚集体的团聚得到了抑制，且油相中颗粒尺寸与初始水相中相比没有变化。小的蛋白质聚集体组装成跨越空间的网络，从而赋予液态油类固体的性质。通过振荡流变学我们得出结论，聚集体在形成网络方面非常有效。在约3%的浓度时，我们就发现G'>G″，且G'与蛋白质浓度成正比，即G'∼c。将分形凝胶网络理论应用于流变学数据，我们推断这些凝胶处于强连接状态，分形维数为2.2。结果表明，蛋白质聚集体除了在水性溶剂中具有众所周知的功能外，还能够在液态油中形成网络。这为设计具有可调流变性质的油凝胶提供了一种新颖且有前景的方法，可应用于例如食品、药品和/或化妆品等领域。
