EFFECTS OF HIGH-PRESSURE ON PROTEINS

The recent interest of the food industry in the high-pressure processi ng of food materials as an alternative or in addition to temperature t reatment requires fundamental studies on the pressure-temperature beha vior of macromolecular food constituents such as proteins. In this pap er we review some basic knowledge on the effects of high pressure on p roteins. These effects are reversible or nonreversible and include cha nges in intra- or intermolecular interactions (noncovalent bonds), in conformation and in solvation, In general, reversible effects are obse rved below 1-2 kbar (e.g., dissociation of polymeric structures into s ubunits). Above 2 kbar, nonreversible effects may include complete ina ctivation of enzymes and denaturation of proteins (unfolding of monome ric proteins, aggregation, and gelation phenomena). Particular attenti on is directed to pressure denaturation, a complex phenomenon dependin g on protein structure, on pressure range, and on other external param eters, for example, temperature, pH, and solvent composition (presence of sugars, salts, and other additives).