Histidine decarboxylase activity of Enterobacter cloacae S15/19 during the production of ripened sausages and its influence on the formation of cadaverine

The histidine decarboxylase activity of Enterobacter cloacae S15/19 was studied during the production process of salchichon, a Spanish ripened sausage. Counts of fecal coliform and histidine decarboxylase bacteria decreased during the production process, showing a good correlation in both inoculated and control samples. In the samples inoculated with Enterobacter cloacae S15/19, fecal coliforms were undetectable the last day of the survey while the population of histidine decarboxylase bacteria was over 2 log MPN/g. Despite the fact that inoculation with Enterobacter cloacae S15/19 increased histidine decarboxylase bacteria counts, no differences were observed in the histamine concentration reached which was undetectable in most of the control and inoculated samples. In contrast, cadaverine concentration increased significantly (P<0.01) in the inoculated samples, suggesting that cadaverine could be used as a hygienic-quality indicator of the raw materials employed in sausage processing.