The quality changes that occur during the frozen storage of bonito (Sarda sarda Bloch, 1793) prepared by different treatments

Abstract

Bonitos (Sarda sarda Bloch, 1793) frozen with different prefreezing and postfreezing treatments at -35 degrees C in an air blast freezer with 5 m/s air velocity were stored at -25,2 degrees C for 6 months. We determined the effects on the sensory properties, total volatile basic nitrogen (TVB-N) and thiobarbituric acid (TBA) values, and the drip loss during the storage period of applying glaze with solution including ascorbic acid for preventing oxidation, of using sodium polyphosphate in order to prevent drip loss during the frozen storage, of removing the internal organs and gills, and of keeping in ice during 24 h prefreezing. The TVB-N content of fish from which the internal organs and gills had been removed was significantly lower. While gutting alone did not affect TBA growth, gutting with icing improved TBA values. Glaze with ascorbic acid was more effective than glaze with water (without ascorbic acid) in preventing lipid oxidation. The chemical and sensory quality of all the fish was good during the frozen storage period.