Glyn O. Phillips Hydrocolloid Research Centre, School of Food and Biological Engineering, and Hubei Collaborative Innovation Centre for Industrial Fermentation, Hubei University of Technology, Wuhan 430068, China; email:
School of Physics and Technology, Wuhan University, Wuhan 430072, China.
Annu Rev Food Sci Technol. 2017 Feb 28;8:493-521. doi: 10.1146/annurev-food-030216-025859. Epub 2017 Jan 12.
Microrheology provides a technique to probe the local viscoelastic properties and dynamics of soft materials at the microscopic level by observing the motion of tracer particles embedded within them. It is divided into passive and active microrheology according to the force exerted on the embedded particles. Particles are driven by thermal fluctuations in passive microrheology, and the linear viscoelasticity of samples can be obtained on the basis of the generalized Stokes-Einstein equation. In active microrheology, tracer particles are controlled by external forces, and measurements can be extended to the nonlinear regime. Microrheology techniques have many advantages such as the need for only small sample amounts and a wider measurable frequency range. In particular, microrheology is able to examine the spatial heterogeneity of samples at the microlevel, which is not possible using traditional rheology. Therefore, microrheology has considerable potential for studying the local mechanical properties and dynamics of soft matter, particularly complex fluids, including solutions, dispersions, and other colloidal systems. Food products such as emulsions, foams, or gels are complex fluids with multiple ingredients and phases. Their macroscopic properties, such as stability and texture, are closely related to the structure and mechanical properties at the microlevel. In this article, the basic principles and methods of microrheology are reviewed, and the latest developments and achievements of microrheology in the field of food science are presented.
微流变学通过观察嵌入其中的示踪粒子的运动，提供了一种在微观水平上探测软物质局部粘弹性性质和动力学的技术。它根据嵌入粒子上施加的力分为被动和主动微流变学。在被动微流变学中，粒子由热涨落驱动，可以根据广义斯托克斯-爱因斯坦方程获得样品的线性粘弹性。在主动微流变学中，示踪粒子由外力控制，可以将测量扩展到非线性区域。微流变学技术具有许多优点，例如仅需要少量样品和更宽的可测量频率范围。特别是，微流变学能够在微观水平上检查样品的空间异质性，这是传统流变学无法做到的。因此，微流变学在研究软物质（特别是复杂流体）的局部力学性质和动力学方面具有相当大的潜力，包括溶液、分散体和其他胶体系统。食品产品如乳液、泡沫或凝胶是具有多种成分和相的复杂流体。它们的宏观性质，如稳定性和质地，与微观水平的结构和力学性质密切相关。本文综述了微流变学的基本原理和方法，并介绍了微流变学在食品科学领域的最新发展和成果。
