ABSTRACT
Functional properties of proteins include the ability to form Œlms and coatings. Proteins are polymers with speciŒc amino acid sequences and molecular structure. Depending on the sequential order of the amino acids, the protein will assume different structures along the polymer chain which will determine the secondary, tertiary, and quaternary structures. The secondary, tertiary, and quaternary structures of proteins can be easily modiŒed to optimize the protein conŒguration, protein interactions, and resulting Œlm properties. Films and coatings based on proteins are edible or biodegradable, depending on formulation, formation method, and modiŒ- cation treatments (Krochta, 2002). As long as food-grade proteins and additives are used and only protein changes due to heating, pH modiŒcation, salt addition, enzymatic modiŒcation, and water removal occur, the resulting Œlm or coating is edible (Krochta and De Mulder-Johnston, 1997).
