Physical properties of food materials

Abstract Physical properties of foods are inevitably involved in food-processing operations, giving useful information on how to handle a raw material and they affect how food will be processed, stored, and consumed. They include thermal, mass, structural, optical, rheological, electrical, and acoustic properties. This chapter covers only some key issues of physical properties of food defining terms and methods. Particle characterization using geometric properties such as size and shape is of great importance for food processing and quality evaluation. Density and porosity terminology are clearly defined to facilitate the understanding of how and when they are used. Mechanical properties and texture of solids are described. Moreover, the texture profile analysis (TPA) technique and the effect of time on a viscoelastic material are presented. The last part of this chapter presents the means of food color evaluation and reviews the color parameters that were evaluated during dry process. Some case studies are presented in the chapter to demonstrate the importance of determining physical properties of food in the food industry.