No abstract

Lactic acid bacteria (LAB) play a central role in several food fermentations, producing lactic acid besides other metabolic actions. Popular fermented foods that rely on the use of LAB include fermented meats, sourdoughs, and fermented dairy products. During fermentation, LAB are frequently accompanied by other microorganisms, such as coagulase‐negative staphylococci (CNS), yeasts, and filamentous fungi. Whereas fermentation was originally a spontaneous and empiric process, most industrial processes make now use of starter cultures to speed up the fermentation process and standardise the end products and to reduce the risks on misfermentation. A drawback of using commercial starter cultures is their suboptimal selection, which is often solely based on mere technological features. Currently, functional starter cultures are being developed to further optimise the process and to yield additional nutritional, safety, and quality benefits. Specific metabolic properties are being sought for, with a focus on novel, interesting molecules that may, for instance, inhibit undesirable microorganisms, display nutraceutical properties, or contribute to flavour and texture attributes.

No 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.

No abstract