Technology-induced selection towards the spoilage microbiota of artisan-type cooked ham packed under modified atmosphere.
The microbiota associated with a highly-perishable Belgian artisan-type cooked ham was analyzed through plating and (GTG)(5)-fingerprinting of isolates throughout its processing chain. The raw tumbled meat was characterized by the presence of a versatile microbiota around 4.8 log(cfu g(-1)), consisting of lactic acid bacteria, staphylococci, Brochothrix thermosphacta, Gram-negative bacteria, and yeasts. Pasteurisation of the ham logs reduced bacterial counts below 2 log(cfu g(-1)) and subsequent manipulations selected for leuconostocs and carnobacteria. Also, B. thermosphacta and several Enterobacteriaceae were found at this stage. During storage in an intermediate high-care area for 2 days, a selection towards certain Enterobacteriaceae (Hafnia alvei, Enterobacter spp., and Pantoea agglomerans) and lactic acid bacteria (mainly vagococci and Streptococcus parauberis) was observed. B. thermosphacta, Leuconostoc carnosum and carnobacteria were also detected, but only after allowing bacterial outgrowth by incubating the meat logs at 7 degrees C for four weeks. After a mild post-pasteurisation process and subsequent handling, incubation of the meat logs at 7 degrees C for four weeks led to outgrowth of Enterobacteriaceae (mainly Enterobacter spp. and Serratia spp.). B. thermosphacta, and lactic acid bacteria (Enterococcus faecalis, Leuc. carnosum, and Carnobacterium maltaromaticum) were also found. After slicing and packaging under modified atmosphere, the microbiota of the refrigerated end-product consisted of leuconostocs, carnobacteria, and B. thermosphacta.
Vasilopoulos
Charalampos
C
Research Group of Industrial Microbiology and Food Biotechnology (IMDO), Faculty of Sciences and Bio-engineering Sciences, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium.
De Maere
Hannelore
H
De Mey
Eveline
E
Paelinck
Hubert
H
De Vuyst
Luc
L
Leroy
Frédéric
F
D000818:Animals; D001419:Bacteria / Q000235:genetics / Q000302:isolation & purification*; D005511:Food Handling; D018857:Food Packaging; D005519:Food Preservation; D008461:Meat Products / Q000382:microbiology*