Aroma compound production by Propionibacterium
Résumé
Propionibacterium freudenreichii is used as a ripening culture for its contribution to the formation of the characteristic holes and flavour in Swiss-type cheeses. This species is able to produce a range of flavour compounds, via various metabolic pathways including central carbon metabolism, membrane synthesis. The enzymes and genes involved in flavour-forming reactions have been partially identified. Many of the activities are strain-dependent in P. freudenreichii and other dairy propionibacteria species, leading to the need of screening approaches to evaluate the flavouring potential of the strains. Biotic and abiotic factors modulate the expression of propionibacteria potential in cheese. The original abilities of propionibacteria compared to lactic acid bacteria offers opportunities to modulate flavour in Swiss-type and other types of cheeses.