Chapter 4. Oral tribology of polysaccharides

Oral tribology deals with the study of friction, wear, and lubrication between oral surfaces that are in relative motion, such as tongue-oral palate, food-tongue, teeth-food, teeth-teeth, etc. Although food material scientists have extensively studied bulk rheology of food, tribology has attracted research attention relatively recently in order to understand the surface interactions between the food, saliva, or food-saliva mixtures and oral surfaces during oral processing. In this chapter, we focus on oral tribology of hydrocolloids, i.e., aqueous dispersions of starch and nonstarch polysaccharides that are often used as fat replacers or bulking agents in food industries. We examine the commercially available and custom-made tribometers that are used to measure the friction force in various food research laboratories. Recent work on polysaccharide-based fluid gels, microgels, and mixed gels are presented, where tribological research is rather limited. Finally, we draw some conclusive remarks on the lubrication mechanisms of polysaccharides and highlight future prospects.