GROWTH OF AEROMONAS-HYDROPHILA AND PLESIOMONAS-SHIGELLOIDES ON COOKED CRAYFISH TAILS DURING COLD-STORAGE UNDER AIR, VACUUM, AND A MODIFIED ATMOSPHERE

Crayfish (Procambarus clarkii) tailmeat samples were sterilized, cooled, and surface-inoculated with approximately log10 4.0 cells/g of Aeromonas hydrophila (ATCC #7965) or log10 3.0 cells/g of Plesiomonas shigelloides (ATCC #14029). Inoculated samples were packaged under air, vacuum, or a commercial modified atmosphere (MA) gas mix containing 80% CO2 and no O2. Throughout 6 d of incubation at either 2 and 8°C (A. hydrophila) or 8, 11, and 14°C (P. shigelloides), samples were analyzed at 2 d intervals for population of the inoculum species. Slight growth of A. hydrophila occurred during air- and vacuum-storage at 2°C. No growth occurred during 2°C MA storage. At 8°C, vacuum and MA storage caused nearly equal inhibition of A. hydrophila growth. P. shigelloides did not grow at 8°C under any treatment. At 11°C, MA storage effectively prevented growth of P. shigelloides, while vacuum storage was slightly less inhibitory. Vacuum storage did not deter growth of P. shigelloides at 14°C, but MA storage had a minor inhibitory effect. Copyright © International Association of Milk, Food and Environmental Sanitarians.