Rheological analysis of dairy products: Instrumentation and Applications to Functional Dairy Products Enriched with Plant-based Ingredients

Food rheology studies how food and beverages flow and deform. Milk and dairy products often contain multiple ingredients and structures that create a complex rheological response. This article aims to thoroughly review the rheological characteristics of various dairy products (milk, concentrated milk, fermented dairy gels, foams and cream, ice cream, butter, and low-fat dairy desserts), focusing on how the composition of dairy mixtures and processing parameters influence their rheological behavior and texture changes. Additionally, the study discusses the most commonly used rheological measurements and instruments in the dairy industry. Results show that measurements like texture profile analysis and fundamental methods, such as small amplitude oscillatory shear (SAOS), large amplitude oscillatory shear (LAOS), and tribology, provide more accurate information than empirical methods like gelometers and penetrometers. However, the colloidal properties and clumping behavior of dairy systems should be considered when choosing the appropriate rheological measurement technique. The study also highlights the trend of using hydrocolloids to improve the texture of dairy gels, especially low-fat dairy desserts, through casein-hydrocolloid linkages. Furthermore, it discusses how adding plant-based ingredients like coffee powder, flaxseed powder, and apple polyphenols in functional dairy products impacts their rheological properties, pointing to future improvements in product quality. Findings show that the interaction between dairy proteins and phenolic compounds significantly influences the texture and sensory qualities of functional dairy products enriched with plant extracts.