ABSTRACT
This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book deals with the physicochemical bases of protein functionality and the structure-function relationships of specific food proteins. Proteins play several important roles in biological and food systems. Some of these include biocatalysts, structural components of cells and organs, contractile proteins, hormones, transport proteins metal chelation, antibodies, protective proteins, and storage proteins as nitrogen and energy source for embryos. The functional behaviors of biologically important proteins and food proteins are dependent on their structures. Four levels of structural hierarchy, namely, primary, secondary, tertiary, and quaternary structures, exist in proteins. Many food proteins, such as cereal, legume, and oilseed proteins, are oligomeric proteins with several subunits. Cereal proteins typically contain more than 35% hydrophobic amino acid residues and a high level of proline residues, and they exist in complex oligomeric states.
