Statistical insights into biogenic amine accumulation in traditional cheeses based on microbial, physicochemical, proteolytic, and technological properties

This observational study aimed to investigate the occurrence and distribution of biogenic amines in a representative set of traditional cheeses, grouped by milk origin (bovine and non-bovine) and cheesemaking technology into hard cheeses, pasta filata cheeses, and soft cheeses. For each sample, a wide set of parameters was analyzed, including gross composition, microbial count (culture-dependent), free amino acids, and biogenic amines (BA). Overall, BA content showed a high variability among cheese categories, reflecting differences in milk origin, extension of ripening, and cheesemaking conditions. Non-bovine cheeses, particularly hard varieties produced from raw ewe milk, exhibited the highest levels of BA, whereas bovine cheeses appeared less affected by prolonged ripening. Univariate correlation analysis indicated that BA accumulation is influenced by multiple interacting factors, including physicochemical parameters, microbial dynamics, and metabolic traits, confirming that the simple availability of precursor amino acids is not sufficient to explain BA formation, thus supporting the role of environmentally modulated decarboxylase activity. Multivariate statistical analysis clarified the relationships among specific BA, microbial groups, and compositional features. Cadaverine, putrescine, and tyramine were associated with high enterococci counts and elevated sodium chloride content, predominantly characterizing non-bovine cheeses. Histamine was mainly linked to proteolysis and ripening-related variables and was characteristic of aged hard and pasta filata cheeses. Soft cheeses were differentiated by pH, moisture, nitrogen fractions, and overall microbial densities, highlighting how compositional and microbiological variability drive BA distribution across cheese types. The results underscore the complex interplay among biochemical, microbiological, and environmental factors in BA formation. A holistic, multi-parameter approach is needed to assess BA risk in cheeses, especially in traditional varieties, and future work should include multi-omics and culture-independent methods to better elucidate the drivers of BA biosynthesis.