부산대학교 도서관

"Nite" and "vojky" are various string-like forms of a traditional cheese in Slovakia. These products are manufactured by shaping of pasteurized or raw cows' or ewes' milk-based lump cheeses after melting in hot water. Unsmoked versions of these cheeses from three producers were studied regarding the contents of microorganisms and volatile aroma-active compounds in four seasons during a year. Culture-based microbiological analysis was carried out using selective media. Because eukaryotic microflora was found to be negligible, culture-independent analysis was focused to prokaryotes, using 16S rDNA amplification coupled to high throughput sequencing on Illumina MiSeq platform (Illumina, San Diego, California, USA). Aroma-active compounds were extracted by headspace solid-phase microextraction and subsequently analysed by gas chromatography-olfactometry supported by gas chromatography-mass spectrometry. Microflora was found to be dominated by Lactococcus spp. with significant levels of Streptococcus spp., Lactobacillus spp. and Enterococcus spp. Dominant aroma-active compounds comprised butanoic acid, diacetyl and 3-methylbutanoic acid, the latter being profound in "nite" produced from unpasteurized ewes' milk. Traditionally produced cheeses contained a more diverse prokaryotic microflora and had a stronger aroma profile containing a rich complex of volatile aroma-active compounds, while "nite" produced from pasteurized cows' milk by industrial process contained a uniform microflora and had a weaker aroma profile. [ABSTRACT FROM AUTHOR]