Industrial Gouda cheese production shows batch-to-batch variations when using the same primary starter culture mixture as well as an impact of the brine on cheese quality

Industrial production of Gouda cheeses is still affected by batch-to-batch variations, partly attributed to the rotational use of different starter culture mixtures. The current study aimed to unravel other variations by following two industrial Gouda cheese productions, made with the same starter culture mixture, up to 100 weeks. A culture-dependent analysis was combined with a culture-independent analysis through amplicon-based high-throughput sequencing (HTS) of the full-length 16S rRNA gene and meta-metabolomics, for both the cheese cores and rinds. Both cheese productions differed significantly in microbial counts throughout ripening. Lactococcus cremoris and Lactococcus lactis were the main species in the cheese cores. Additionally, Leuconostoc pseudomesenteroides was abundantly present, whereas Lacticaseibacillus paracasei was only abundant in one production, the cheeses of which had higher concentrations of free amino acids up to 26 weeks of ripening, and higher concentrations of D-lactic acid. The company's house microbiota differed from the cheese microbiota, with the exception that Loigolactobacillus rennini and Tetragenococcus halophilus were found in the brine and the cheeses . The former species caused high biogenic amine concentrations in the rinds during ripening. The microbial development of a new brine, including the fungal evolution by applying amplicon-based HTS of the whole fungal rRNA transcribed unit, went fast. However, the cheeses brined in the new brine did not contain Loil. rennini and the associated biogenic amines.