Contribution of several cheese-ripening microbial associations to aroma compound production

The aromatic potential of various cocultures of yeasts, Brevibacterium linens and lactic acid bacteria (LAB) was studied in cheese-based medium. Three yeasts (Debaryomyces hansenii, Geotrichum candidum and Kluyveromyces lactis) were cultivated in association with B. linens, in the presence or in the absence of LAB - added as the commercial lactic acid starter Flora Danica ® . Various parameters were analysed such as aroma compound production, the growth of each microorganism and lactose/lactate degradation. All tested yeasts could grow in all the associations regardless of the presence or the absence of LAB. LAB enhanced the growth of B. linens in D. han- senii associations, but they reduced B. linens' growth when associated with K. lactis. When cultiva- ted alone, LAB produced very few aroma compounds and in lesser amount than the yeast-B. linens associations. In pure cultures of LAB, ethanol was the major volatile compound, and only scanty amounts of other volatile compounds were produced. The K. lactis-B. linens association exhibited the most diversified aroma compound profile with high quantities of S-methyl thioacetate and ethyl acetate. LAB promoted the synthesis of volatile sulphur compounds in this association. Ripening / interaction / microbial association / aroma compound