Effect of high pressure on the microbiological quality of cooked chicken during storage at normal and abuse refrigeration temperatures.
Vacuum-packaged cooked poultry meat was treated at a range of pressures (400-600 MPa) and hold times (1, 2 and 10 min), followed by storage at 4 degrees , 8 degrees or 12 degrees C for up to 35 days. Weissella viridescens was found to be the dominant microorganism in the pressure-treated meat, constituting 100% of the microflora identified at 500 and 600 MPa. None of the pressure-treated samples had obvious signs of spoilage during the 35 day storage period, even when the Weissella count was >7 log(10) cfu/g. Studies on a typical W. viridescens isolate showed it to be relatively pressure-resistant in poultry meat, with <1 log reduction in numbers after a treatment of 2 min at 600 MPa. Agar diffusion assays showed that the isolate also caused the inhibition of a number of Gram-positive and Gram-negative pathogens, including strains of Clostridium botulinum, Listeria monocytogenes, Bacillus cereus and Escherichia coli. The selection of a pressure-resistant organism, such as this Weissella sp. could be advantageous in extending the shelf-life, and also microbiological safety, of the cooked meat, as it could give protection in addition to the pressure treatment itself.
Food Microbiology Branch, Agriculture, Food and Environmental Science Division, Agri-Food and Biosciences Institute, Newforge Lane, Belfast BT9 5PX, Northern Ireland, UK. margaret.patterson@afbini.gov.uk <margaret.patterson@afbini.gov.uk>
Margaret F
MF
Patterson
Alan M
AM
McKay
Malachy
M
Connolly
Mark
M
Linton
D000818:Animals; D001419:Bacteria / Q000145:classification / Q000254:growth & development / Q000302:isolation & purification; D002645:Chickens; D003296:Cooking; D005511:Food Handling / Q000379:methods; D005516:Food Microbiology; D005519:Food Preservation / Q000379:methods*; D056584:Leuconostocaceae / Q000254:growth & development / Q000302:isolation & purification; D008460:Meat / Q000382:microbiology*; D056265:Microbial Interactions; D011312:Pressure; D012034:Refrigeration / Q000379:methods*