Detection of Biogenic Amines and Tyramine-Producing Bacteria in Fermented Sausages from Switzerland

Fermented foods can cause human illness because of the unhealthy effect of biogenic amines (BAs) that accumulate by decarboxylation of free amino acids. Salami-type fermented sausages can contain BAs, but which bacteria and environmental factors contribute to BA production is not clear. Sixty-two sausages purchased from Swiss markets were evaluated for decarboxylating bacterial strains and concentrations of the BAs cadaverine, histamine, putrescine, and tyramine. Based on the size and number of employees of the meat processing plants, sausages were separated into two groups: artisanal and industrial. Concentrations of all four BAs were higher in industrial sausages than in artisanal sausages. Tyramine was the major BA detected in 46 of 62 sausages, at a maximum concentration of 785.22 mg/kg. Enterococci and coagulase-negative staphylococci (mainly the meat starter culture Staphylococcus xylosus) were the main tyramine producers. Putrescine was found in 20 of 62 samples, at a maximum concentration of 707.77 mg/kg. Concentrations of these two BAs were significantly correlated (P = 0.0407). Cadaverine and histamine were detected in nine and eight samples, respectively, and both were found in significantly higher concentrations (P = 0.019 and 0.036, respectively) in industrial sausages. Based on the tyramine concentration, five groups of fermented sausages were identified: group 1, very high concentrations (>700 mg/kg); group 2, high concentrations (400 to 700 mg/kg); group 3, moderate concentrations (200 to 400 mg/kg); group 4, low concentrations (<200 mg/kg); group 5, concentrations below the detection limit (0.05 mg/kg). Product samples with tyramine concentrations>200 mg/kg were considered of lower quality because consumption of such samples could be unhealthy for sensitive consumers. HIGHLIGHTS BAs concentrations were higher in industrial than in artisanal salami-type sausages. Putrescine was always detected when high concentrations of tyramine were present. The meat starter culture S. xylosus may contain the tyramine decarboxylase gene.