Acta Scientiarum Polonorum Technologia Alimentaria

Abstract Catalitic effects of calcium chloride on ripening of salted Baltic herring were studied. Herring carcasses, fresh or frozen/thawed, were covered with 12% NaCl solution with 0, 0.1, 0.5 or 1.0% addition of calcium chloride; the fish brine weight ratio was 1:1. Samples were incubated for 18 days at 7+1oC and assayed after 1, 3, 5, 7, 9, 11, 15 and 18 days of ripening. The assays involved determination of pH, water content, and contents of protein hydrolysis products (PHP) soluble in 6% NaCl and in 5% tricholoacetic acid (TCA) (biuret and modified Lowry methods), as well as fish meat sensory desirability. Calcium chloride addition was found to primarily enhance the release of 6% NaCl-soluble, 5% TCA-precipitated PHP; the 5% TCA-soluble TCA release was less enhanced, while almost no tyrosine release enhancement could be detected. Calcium chloride enrichment was also found to act as a salted herring preservative by extending the induction phase, preceding that of intensive trimethylamine increase. Calcium chloride improved salted Baltic herring meat texture, the effect being more pronounced in fresh than in fro-zen/thawed fish. The best texture was shown by those fish ripened in 0.1% calcium chlo-ride enriched brine. In practice, application of calcium chloride as a ripening catalyst can be limited by its sensory detection in the final product. For this reason, the maximum cal-cium chloride concentration in brine should not exceed 0.5%.