Formation of supermolecular assemblies on colloidal surfaces

食品是含有胶体颗粒（蛋白质聚集体、乳剂液滴）的多相系统。生物聚合物可以与胶体粒子相互作用，形成超分子组合。虽然我们开始了解如何控制这些相互作用，但我们只是在研究它们如何影响稳定性，质地和微观结构变化的开始阶段。将胶体现象与真正的食物联系起来的挑战仍然存在。我们建议研究多组分系统中界面交换的复杂动力学，特别是在热处理和酸化等加工条件下。为了在尽可能接近真实系统的条件下工作，生物聚合物的相互作用不仅需要用传统的分析工具来研究，还需要使用新的技术来研究，这些技术可以在不干扰结构的情况下测量物理化学性质。事实上，研究混合体系的初期不稳定或凝胶化是一项非常困难的任务，因为测量它们的性质会导致它们的结构改变。我们已经成功地开发了使用超声波和漫射波光谱学来测量这些系统而不会中断的方法。这些技术可以在静态条件下测量浓缩的、不透明的样品，不需要稀释或任何其他样品干扰。我们证明，现在可以观察到相互作用的开始阶段和聚集的动力学。我们的实验室在加拿大和北美在这方面的研究和使用这些技术是独一无二的。我们建议使用日益复杂的模型系统来观察生物聚合物相互作用的影响。这种基本方法将使我们能够更好地理解参数并解释来自超声和扩散波光谱对浓缩食品胶体的数据。然后，我们将能够解释聚合物和胶体之间相互作用的动力学，并确定这些组合如何影响加工过程中多组分系统的行为。我们的研究成果将代表我们对食物系统结构形成的理解的转折点。

Foods are multiphase systems containing colloidal particles (protein aggregates, emulsion droplets). Biopolymers can interact with the colloid particles, creating supermolecular assemblies. Although we are starting to understand how to control these interactions, we are just at the beginning stages of the study of how they affect changes in stability, texture and microstructure. The challenge of relating colloidal phenomena to real foods also still remains. We are proposing to study the complex dynamics of exchanges at the interface in multicomponent systems, especially under processing conditions such as heat treatment and acidification. In an effort to work under conditions as close as possible to the real systems, biopolymer interactions need to be studied not only with traditional analytical tools, but also with novel techniques which allow measurement of the physico-chemical properties without disturbing the structure. In fact, a very difficult task is to study the incipient destabilization or gelation in mixed systems, as the very act of measuring their properties causes them to change the structure. We have successfully developed ways to measure these systems without disruption using ultrasound and diffusing wave spectroscopy. These techniques can measure concentrated, opaque samples, under quiescent conditions, with no need for dilution or any other sample disturbance. We demonstrated that the beginning stages of the interactions and the dynamics of aggregation can now be observed. Our laboratory is unique in Canada and in North America in this area of research and the use of these techniques. We are proposing to use model systems of increasing complexity to look at the effect of biopolymer interactions. This basic approach will allow us to better understand the parameters and interpret data from ultrasound and diffusing wave spectroscopy on concentrated food colloids. We will then be able to interpret the dynamics of interactions between polymers and colloids, and determine how these assemblies affect the behaviour of multi-component systems during processing. Our research outcomes will represent a turning point in our understanding of the formation of structure in food systems.