Effect of pre-icing duration on quality deterioration of iced Nile perch (Lates niloticus)

Quality deterioration of Nile perch iced 0, 3 and 6 h after landing was monitored to determine the effect of delayed icing on stability during storage on ice. Free fatty acids, volatile nitrogen bases and mesophilic microbial counts increased during the pre-icing duration. Delayed icing also increased the rate of lipolysis, degradation of nitrogenous compounds and growth of mesophilic microbes during subsequent storage on ice and reduced the time required for development of off odours. Psychrotrophic plate counts were, however, not affected by pre-icing duration. It was concluded that spoilage of Nile perch stored on ice is hastened by delay to ice and that mesophiles play a more important role in the spoilage of Nile perch, even when stored on ice.