An evaluation of the effect of storage and processing temperatures on the microbiological status of sous vide extended shelf-life products

摘要

The microbiological and organoleptic quality of selected sous vide products was monitored over a storage period of up to five weeks at 3 deg C and 8 deg C, respectively. Sous vide products stored at the recommended temperature of 3 deg C showed negligible microbial growth and were found to be organoleptically acceptable throughout the storage period. Total plate counts at the end of the fourth week of storage were in the range <110-7 X 10~3 CFU/g for all 19 products under study. Listeria monocytogenes, Salmonella, Clostridium perfringens, Bacillus cereus and Enterobacteriaceae were not detected in any of the processed samples. At 8 deg C, under temperature abuse conditions, while some products had acceptable microbial levels of 10~2-10~4 CFU/g after three weeks, others such as chicken chasseur had counts above 10~6 CFU/g by the second week of storage. Lactic acid bacteria and Pseudomonas species were dominant in the microbial flora of spoilt samples and B. cereus (>3 X 10~4 CFU/g) was isolated from spoilt chicken chasseur samples in the fourth week of storage at 8 deg C. Critical factors affecting sous vide product safety are discussed.