Comparative Growth Rates of Salmonella typhimurium and Pseudomonas fragi on Cooked Crab Meat Stored Under Air and Modified Atmosphere.

Crab meat packaged in plastic (polypropylene, Fisher) jars was sterilized, cooled, and inoculated with approximately 10 cells/g each of Salmonella typhimurium and Pseudomonas fragi . Inoculated samples were packaged either under air or a commercial modified atmosphere (MA) gas mix containing 50% CO/10% O/balance proprietary. These samples were stored at 7 and 11°C. At 0, 2, 4, and 6 d after inoculation, three samples per treatment at each temperature were tested for populations of inoculum species. S. typhimurium did not grow under either atmosphere at 7°C but grew under air and MA at 11 °C. MA-storage slowed the growth of both S. typhimurium and P. fragi at 11°C, although growth of S. typhimurium was more severely inhibited. Use of 50% CO/10% O/balance proprietary MA-storage may greatly extend the shelf life of crab meat, but in the absence of proper refrigeration, it cannot be relied upon to eliminate the risk of salmonellosis.