Tyrosine and Histidine Decarboxylase Activities of Pediococcus cerevisiae and Lactobacillus Species and the Production of Tyramine in Fermented Sausages

Abstract
In investigating formation of tyramine and histamine in a model system, it was found that four commercial sausage starter cultures did not exhibit appreciable tyrosine or histidine decarboxylase activity. In addition, other species of Pediococcus cerevisiae and Lactobacillus did not display appreciable decarboxylase activity. Mixtures of P. cerevisiae and Lactobacillus plantarum were also unable to produce significant levels of these amines. One species of Streptococcus tested was able to produce 34.5 μg of tyramine/hour under the assay conditions. When P. cerevisiae and L. plantarum were used as starter cultures to prepare sausages, it was found that this treatment resulted in lower tyramine levels (approximately 200 μ/g) than when the Streptococcus sp. was used as a starter culture (approximately 300 μ/g). However, the use of P. cerevisiae and L. plantarum did not result in a significantly lower tyramine level than when no starter culture was used.