Modulation of globular protein functionality by weakly interacting cosolvents

Globular proteins are utilized in food, pharmaceutical, and health-care products because of their unique functional attributes, for example, enzyme catalysis, ligand binding and transport, surface activity and self-association. The expression of these functional attributes in a particular product depends on the molecular structure, chemical environment and thermal-mechanical history of the proteins. The optimization of the design and operation of processing technologies used to manufacture protein-containing materials depends on a thorough understanding of the influence of processing conditions and material composition on protein properties. This paper focuses on the impact of weakly interacting neutral cosolvents (such as sugars and polyols) on the structural, thermodynamic and functional properties of globular proteins in foods. The physicochemical mechanisms by which these cosolvents can modulate protein functionality are highlighted, that is, differential interactions and steric exclusion. Previous studies of the impact of cosolvents on protein functionality that are relevant to foods are reviewed, for example, water solubility, stabilization, emulsification, foaming, gelation, enzyme catalysis, and flavor binding.