Effects of high hydrostatic pressure-thawing on pork meat

Frozen pork meat was thawed under high pressure (100-500MPa) and physicochemical and histological parameters of thawed meat (thawing loss, tenderness, color, drip, ultrastructure, etc.) were compared with those of meat thawed by running water. Effects on physicochemical properties. The meat drip decreased by high hydrostatic pressure-thawing, and the water holding capacity of the meat improved. The discoloration of the meat induced by high pressure-thawing was not recognized by naked eyes up to the pressurization of 200MPa. The meat tenderization was induced during high pressure-thawing. When the frozen pork was pressurized at 200MPa, the most desirable results were obtained. Over 200MPa however, unfavorable changes were brought about by high pressure-thawing. Effects on ultrastructure and myofibrillar proteins. The regular structure of myofibrils was gradually lost with an increase in the pressure applied, and remarkable changes were observed in the meat thawed by pressure above 200MPa. The measurements of the size distribution of the myofibrils prepared from high pressure-thawed meats indicated that frequency of distribution centered on a certain length with increasing pressure applied, differing from the progress of the fragmentation as observed in the myofibrils prepared from pressurized meats. The SDS-PAGE analysis showed the progressive solubilisation of alpha-actinin, troponin T, tropomyosin, and myosin light chain (MLC) in the meat thawed at pressure above 200MPa. These effects caused by high hydrostatic pressure-thawing are applicable to meat processing. It should be applied to the meat products requiring no long-time heating, such as cured smoked pork, roast beef, tataki, (mince-meat) etc.