A Review of Processing Techniques and Rheological Properties of Yogurts

Abstract

The rheology of yogurt, a critical factor influencing its texture, stability, and sensory appeal from production to consumption is explored in this review. Yogurt undergoes a transformation from a Newtonian liquid to a non-Newtonian thixotropic gel during fermentation, a process shaped by factors such as milk source, starter culture, and fat content. Recent advances in non-thermal treatments, such as ultrasound, microfiltration, high-pressure processing (HPP), and ultraviolet C (UV-C) light treatment, promise to enhance nutritional and sensory qualities of yogurt. Additionally, incorporating herbs and fruits into yogurt not only diversifies consumer options but also affects its texture, viscosity, and overall mouthfeel. The review examines how different yogurt styles-set, stirred, Greek, and drinkable-develop unique textures through varied production processes. Advances in rheological techniques and microstructural analysis have deepened our understanding of the interactions between proteins and fat globules, providing insights into the complex gel network of yogurt. Despite significant progress, further research is needed in areas such as non-destructive rheological testing during production, the impact of extended storage, and the development of plant-based yogurt alternatives. The insights are valuable for the dairy industry to support innovation and meet growing consumer demands.

Keywords: Newtonian liquid; dairy products; microstructure; thixotropic gel.