HIGH PRESSURE PROCESSING EFFECTS ON FISH PROTEINS

摘要

Salted pastes of surimi, a myofibrillar concentrate of fish muscle, gel at pressures near 300 MPa. High pressure processing has been thought to induce de-naturation and gelation of myofibrillar proteins mainly by disruption of protein intramolecular hydrophobic interactions which subsequently reform inten-nolecularly. We have shown that pressure-induced surimi gels evidence disul-fide bonding as well. Endogenous transglutaminase (TGase) evidently survives the pressure treatment, and subsequent TGase-mediated setting of Alaska pollock surimi pastes at 25 ℃ results in very strong gels as compared to those prepared without prior pressurization. High pressure during freezing or thawing greatly accelerates these operations and can reduce ice crystal size and associated tissue damage. Yet pressure treatment can destabilize proteins which might lower fish quality. Infusion of certain carbohydrates into muscle prior to pressure-assisted freezing/thawing can achieve both baroprotection and cryoprotection of the muscle proteins. Pressure treatment has not proven useful for inactivation of proteolytic enzymes that degrade fish quality.