The effects of nisin on the growth of foodborne pathogens and biogenic amine formation: in vivo and in vitro studies

Abstract

The effects of different concentrations of nisin on the biogenic amine formation in seabass (Dicentrarchus labrax) fillets stored at 4 +/- 2 degrees C (in vivo) and also on foodborne pathogens (in vitro) in amino acid decarboxylase broth were investigated. The in vitro impact of nisin on microbial growth and biogenic amine production was observed in histidine and tyrosine decarboxylase broth (TDB). The results showed that Gram-positive foodborne pathogens were more sensitive (especially 1ml/100 ml nisin) than Gram-negative groups. Bacterial loads in histidine decarboxylase broth (HDB) and TDB were not always correlated with biogenic amine formation. The impact of nisin on biogenic amine production varied with specific microbial strains and broth used. The results demonstrated that nisin inhibited the microbial growth, resulting in reduced biogenic amine production in seabass fillets. The application of nisin (especially 0.8 %) as in vivo preserved the microbiologic quality and thus reduced biogenic amine production. Consequently, nisin has the potential to be used as a novel antimicrobial agent against foodborne pathogen and food spoilage bacteria that produce biogenic amines in foods.