Rheology and tribology assessment of foods

Texture and flavor are the basis of our eating experience. Texture of food, studied in food rheology, only mimics deformation of food during handling and/or at early stages of the eating process resulting in an incomplete or inaccurate elucidation of food texture and eventually oral perception of texture (Chen and Stokes, 2012). Rheological testing mimics initial deformation, whereas, on the other hand, tribological testing mimics in-mouth food manipulations by lubricated interacting surfaces in relative motion (van Aken, 2010). Therefore, the oral perception of food, texture, and mouthfeel corresponding to food rheological and tribological properties can clearly be defined by a combination of bulk and surface properties (lubricated thin-film properties) (Malone et al., 2003, Stokes, 2012). To be in the perspective of this book's aim, we shall look onto food application. The main objective of this chapter is to use the fundamentals of rheology and soft-contact tribology to gain an understanding of food characterization, either independently or simultaneously. Note that we will not be diving deep into technical content of rheology and tribology but would rather have a holistic view on the topic along with its application in the food industry.