Evaluation of the spoilage lactic acid bacteria in modified-atmosphere-packaged artisan-type cooked ham using culture-dependent and culture-independent approaches.
OBJECTIVE
To investigate microbial diversity and population dynamics of spoilage-sensitive modified-atmosphere-packaged (MAP) artisan-type cooked ham in relation to storage temperature.


RESULTS
Modified-atmosphere-packaged cooked ham samples were stored at different temperatures (4, 7, 12 and 26 degrees C). Traditional methods were combined with polymerase chain reaction (PCR)-based techniques, i.e. a culture-dependent, repetitive DNA sequence-based method (rep-PCR) and a culture-independent approach (PCR-denaturing gradient gel electrophoresis of 16S rRNA gene fragments; PCR-DGGE). rep-PCR on DNA extracted from MRS isolates indicated that Leuconostoc carnosum and Enterococcus faecalis prevailed at all temperatures, with the latter becoming more important above 7 degrees C. PCR-DGGE indicated the additional presence of Carnobacterium divergens and Brochothrix thermosphacta at all temperatures. Discriminant analysis related variation within the Leuc. carnosum cluster to the storage temperature. High performance liquid chromatography revealed that lactic acid was the main metabolite because of glucose consumption.


CONCLUSIONS
Leuconostoc carnosum, C. divergens, E. faecalis and Br. thermosphacta are the main spoilage bacteria of artisan-type MAP cooked ham. Their population dynamics are affected by storage temperature.


CONCLUSIONS
Temperature can condition the development of spoilage in artisan-type MAP cooked ham, acting at both species and biotype level.
Vasilopoulos
C
C
Research Group of Industrial Microbiology and Food Biotechnology (IMDO), Department of Applied Biological Sciences and Engineering, Vrije Universiteit Brussel, Brussels, Belgium.
Ravyts
F
F
De Maere
H
H
De Mey
E
E
Paelinck
H
H
De Vuyst
L
L
Leroy
F
F
D000818:Animals; D015169:Colony Count, Microbial; D003296:Cooking; D004269:DNA, Bacterial / Q000032:analysis; D004591:Electrophoresis, Polyacrylamide Gel; D013293:Enterococcus faecalis / Q000235:genetics / Q000302:isolation & purification; D005516:Food Microbiology; D018857:Food Packaging; D005519:Food Preservation; D005947:Glucose / Q000378:metabolism; D007777:Lactobacillaceae / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D007934:Leuconostoc / Q000235:genetics / Q000302:isolation & purification; D008460:Meat; D016133:Polymerase Chain Reaction / Q000379:methods; D021521:Ribotyping; D013552:Swine; D013696:Temperature
D004269:DNA, Bacterial; D005947:Glucose