Book excerpt: The book is devoted to expanding current views on the phenomena of protein functionality in food systems. Protein functionalities in foods have been the object ofextensive research over the last thirty to forty years and significant progress has been made in understanding the mechanism and factors influencing the functionality of proteins. The functionality of proteins is one of the fastest developing fields in the studies of protein utilization in foods. Currently, a broad spectrum of data related to protein functionality in food systems has been collected, however, much more needs to be known. In this volume, the most important functional properties offood proteins are presented: Protein solubility, water holding capacity and fat binding, emulsifying, foaming, and gelling properties as affected by protein source, environmental factors (pH, temperature, ionic strength) and protein concentration; Relationships between protein conformation, physicochemical properties, and functional properties; Protein functional properties as influenced by various food processing conditions, particularly heat treatment, dehydration, freezing and storage when frozen, extraction and other processes; Effects ofprotein modification on the enhancementofprotein functionality; Utilization ofvarious proteins in improving functional properties in food systems. Those aspects of protein functionality are presented which the author believes to be interesting and most important for protein utilization in food systems. The book is recommended to students and food scientists engaged in food protein research and food industry research, and development scientists. Table ofContents Introduction 1 References 5 Chapter 1 Solubility ofProteins. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 1. 1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 1. 1. 1 Factors Affecting Solubility ofProteins. . . . . . . . . . . . . . . . . . . . . . . .