Zeta Potential of Food Matrices

Food matrices contain electrically charged particles, which interact with each other and with the media and are produced via several interface processes and mechanisms. The understanding of electric charge interactions is complex and essential towards the development of food systems since they can determine the type of particle-particle and particle-media interactions. They strongly affect stability, rheological behavior, sedimentation, re-dispersion, filtration, shelf life, texture, flavor, and color; thus, importantly influencing food structure and stability. One of the most useful parameters that allow the study of electric interactions in food systems is the zeta potential (ZP). It is possible to find a variety of laboratory instruments designed for its evaluation. ZP is an important property for the characterization of dispersed systems in which sample preparation and measuring methods play a key role to obtain reliable and reproducible results. The use of this parameter has increased in a number of fluid food systems such as alcoholic beverages, juices, extracts, coffee, milk, yoghurt, and edible films, most of which are described in this review. There is a wide amplitude in the number of relevant publications in the literature involving ZP for different products and this is reflected in the length of the different sections of this document. This work depicts a thorough review of the main theoretical principles, applications, and relevance of this parameter in food science and technology.