Freezing Preservation of Alaska Pollack

Alaska pollack tends to have “spongy meat” on frozen storage. It is suggested that vacuum freezing may be effective for this prevention because of the utilization of dehydration and quick freezing at the same time. In this study it was examined. Cut meat of Alaska pollock was frozen by three different methods, vacuum freezing, air blast freezing (3m/sec) at -35°C and still air freezing at -30°C, and stored at -25°, -15° and -5°C for 3 months. At a definite storage interval, the following determinations of samples were examined. Immediately after freezing, “spongy meat” was formed in samples of still air freezing. In those of the other freezings they were formed after storing for one month at -5°C. The amount of soluble nitrogen was constant for three months at -25°C storage, but at -5°C storage it decreased rapidly with the storage period. Expressible drip increased as storage period was longer, especially at high storage temperature. Taste became wrong with these changes. Alaska pollack was lost about 15% of moisture by vacuum freezing. This effect of dehydration would be shown as the ability of freezing preservation of Alaska pollack for 3 months at a temperature as high as -15°C without formation of “spongy meat”.