Evaluation of the spoilage lactic acid bacteria in modified-atmosphere-packaged artisan-type cooked ham using culture-dependent and culture-independent approaches

Abstract

Aims: To investigate microbial diversity and population dynamics of spoilage‐sensitive modified‐atmosphere‐packaged (MAP) artisan‐type cooked ham in relation to storage temperature. Methods and Results: Modified‐atmosphere‐packaged cooked ham samples were stored at different temperatures (4, 7, 12 and 26°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°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. Significance and Impact of the Study: Temperature can condition the development of spoilage in artisan‐type MAP cooked ham, acting at both species and biotype level.

Safety and quality assessment of ready-to-eat pork products in the cold chain

“…In this study, total LAB and Leuconostoc did not develop at low temperature (2°C), except after 48 days of storage, but a count number exceeding 8 Log CFU g À1 was detected at 8°C, 12°C and 15°C just after 1 week of storage. Similar results were published by Vasilopoulos et al (2008) who found that Lc. carnosum represented 91-71% of the total MRS agar population from 4 to 12°C.…”

“…Incubation at 30°C or 15°C of MRS agar did not make a difference in the obtained value for the total LAB. Vasilopoulos et al (2008) reported same variation range of Br. thermosphacta counts (between 4 and 7 Log CFU g À1 ) for spoilage experiments in MAP artisan-type sliced cooked ham incubated at 4, 7, 12, 26°C during respectively 57, 56, 35 and 24 days.…”

Quantifying Variability in Growth and Thermal Inactivation Kinetics of Lactobacillus plantarum

“…Although strain variability in growth and thermal inactivation kinetics has been reported for pathogens, limited information is available for spoilage microorganisms (19)(20)(21)(22)(23). To extend the knowledge of variability in growth and thermal resistance of spoilage microorganisms, Lactobacillus plantarum was chosen as a model species not only because it is often found as contaminant in different food products (24)(25)(26)(27)(28)(29)(30)(31) but also based on the availability of growth and thermal inactivation data in literature (22,23,(32)(33)(34) to benchmark microbiological variability. Although high diversity in genomic and phenotypic levels of L. plantarum have been reported (1,35,36), none of the studies focused on the quantification of strain variability in growth and thermal resistance.…”

Microbiota de jamones de cerdo cocidos asociada al deterioro por abombamiento del empaque

“…Microorganismos como Carnobacterium, Pediococcus, Enterococcus y Brochothrix thermosphacta, no fueron encontrados en las muestras trabajadas (4,19,20). En relación a esto, las condiciones del empaque favorecen el desarrollo de las BAL como los Lactobacillus spp., aislados en mayor proporción del producto terminado que se han introducido en alguna de las etapas del proceso.…”