ABSTRACT
High-pressure processing of biological macromolecules has received tremendous research interest for its potential benets in functionality leading to newer product development with desirable structure (Ledward et al. 1995). In 1914, Bridgman reported that proteins (egg white) could be coagulated under certain conditions, demonstrating that high pressure, despite having a lethal affect on some microorganisms, could affect protein reactivity. The denaturation of proteins under high pressure is now well established. Pressure affects protein structure at the secondary, tertiary, and quaternary levels, leading in general to protein denaturation, aggregation, and gelation (Silva and Weber 1993; Balny and Masson 1993; Balny et al. 2002; Silva et al. 2001). The native structure of a protein (conformation) is the result of a delicate balance between stabilizing and destabilizing interactions within the polypeptide chains and with a solvent (Lullien-Pellerin and Balny 2002). Pressure destabilizes the balance of intramolecular and solvent-protein interactions. Water is commonly used as a high-pressure medium and it has a signicant effect on protein structure under high pressure (Heremans et al. 2000). Thermal denaturation of proteins occurs with protein unfolding by breaking of covalent bonds. Contrary to thermal denaturation, pressure-induced denaturation mechanisms are somewhat different (Knorr, Heinz, and Buckow 2006). The pressure causes change/ breakage in ionic bonds of protein structure (Hayakawa et al. 1996) and also pressure is able to affect the protein structure, at the secondary, tertiary, and quaternary levels, leading in general to protein denaturation (Silva and Weber 1993).
