Effects of immersion freezing with coolant on the quality of grouper (?<i>Epinephelus fuscoguttatus</i> ×? <i>Epinephelus lanceolatus</i>) during frozen storage

In this study, we evaluated the effects of immersion freezing (IF) with coolant and air (AF) techniques different storage temperature (?18°C ?30°C) on quality groupers following frozen storage. Water loss rate, total volatile basic nitrogen, K-value, were positively correlated time. The pH first decreased then increased. Destruction muscle fiber structure led to changes in grouper texture characteristics including hardness, cohesiveness, springiness, chewiness. IF-30°C samples retained highest after storage, followed by IF-18°C AF-18°C samples. Immersion limited protein denaturation, water loss, contributed formation uniformly distributed ice crystals, decreasing microstructure damage. is a promising technique for preserving groupers, (propylene glycol, oligosaccharides salts) used study has potential applications processing industry.