SLUSH-ICE CHILLING PROCESS COULD AFFECT SURVIVAL/GROWTH OF Salmonella spp. AND LOWER MICROBIAL FLORA IN SILURIFORMES

Slush-ice chilling is a process used to lower fish/fillet temperature quickly and effectively prior to packaging/freezing the product. Howev er, little is known about the effect of this system on fillets' safety and quality. This study was to determine the fate of Salmonella spp . and microbial load on catfish (Ictalurus furcatus x Ictalurus punctatus )  fillets subjected to  simulated slush-ice chilling and refrigerated storage conditions . Catfish fillets  inoculated with a cocktail of Salmonella strains were then subjected to  a mixture of slush ice and brine. Samples were held in a cooler at 2°C for up to 12 days to enumerate Salmonella spp. Additionally, fillets taken before-water chill, after-water chill, and after 24-h slush-ice, were stored in a cooler at 2°C for up to 12 days to analyze psychotrophic plate (PPC), total coliforms (TCC), and generic E. coli counts. Salmonella counts were  slightly  reduced (P≤0.05) between 0.55 - 0.83 log CFU/g by slush ice treatments (0% - 4.5% salt). Salmonella reduction was similar (P>0.05) among all treatments after 12 d of storage. Psychotrophs, coliforms, and E. coli counts were similar (P>0.05) among fillets collected before and after 24 h in slush ice. Under the assessed conditions, slush-ice treatments had minimal impact on Salmonella spp. and did not have a residual effect during refrigerated storage. Psychrotrophic plate counts (PPC) increased similarly during refrigerated storage, regardless of chilling process.