Abstract: The aim of the present study was to analyse the influence of non-starter lactic acid bacteria (NSLAB) on Swiss-type cheese quality. Lactobacillus brevis, Lactobacillus plantarum and Lactobacillus paracasei were detected in the same raw and pasteurised milk and cheese samples. Our study showed that non-starter lactic acid bacteria concentration in pasteurised milk varied from 1 to 12 CFU mL-1, but during ripening reaching 3.16*108 CFU g-1. The population of young cheese was comprised of Lactobacillus paracasei, Lactobacillus plantarum and Lactobacillus brevis but in matured cheese Lactobacillus paracasei dominated. NSLAB impact flavour development in Swiss-type cheese. Differences in the detected aroma compounds are observed among the samples of analysed cheeses. Individually detected aroma compounds in cheeses are able to impart different flavour notes, however, in certain combinations uncharacteristic aroma can occur. Among determined volatiles, butanoic acid presents in different quantities, indicating the influence of sporeforming bacteria on Swiss-type cheese production, too. Detected aroma compounds and their concentrations in analysed cheeses do not allow assuring the undesirable impact of NSLAB representative - L.paracesei on the Swiss-type cheese flavour, but cheese moisture and salt content, as well as interactions among cheese microflora representatives influence quality of produced cheese.
Keywords: mesophilic heterofermentative lactobacilli, raw milk, pasteurised milk, cheese