Suitability of lactic acid bacteria and deriving antibacterial preparations to enhance shelf-life and consumer safety of emulsion type sausages

Ready-to-eat (RTE) sliced emulsion type sausages are sensitive to recontamination with Listeria (L.) monocytogenes during processing and packaging steps. Since Listeria spp. are able to grow on those products under cold storage conditions, taking steps to reduce the recontamination risk and implementing antibacterial hurdles contribute to consumer safety and increase the product quality. With this study data about the suitability of culture broth, cell-free supernatant (CFS) or concentrated bacteriocin preparations (CFSconc) of bacteriocinproducing lactic acid bacteria (LAB) obtained from fermented sausages from Germany as protective culture or antibacterial additive were provided. In different challenge tests, the potential of selected LAB or their preparations were investigated for their potential to reduce growth of L. monocytogenes and/or Brochothrix (B.) thermosphacta on sliced RTE emulsion type sausages under modified atmosphere or vacuum during refrigerated storage for a 21-day period. Applied LAB culture broth and CFS could not reduce the growth of L. monocytogenes or B. thermosphacta. On the other hand, samples treated with CFSconc obtained from Pediococcus spp. strains showed a significant inhibition (p < 0.05) of more than 1.5 log(10) of the applied L. monocytogenes strains during the storage period. The growth of B. thermosphacta could not be influenced. Thereby, the need for concentrating preparations was shown to be important to obtain a suitable antibacterial preparation that would contribute to consumer safety and food quality when applied as a protective additive.

Automated summary

The study showed that CFSconc obtained from Pediococcus spp. strains significantly inhibited the growth of applied L. monocytogenes strains during the storage period, while LAB culture broth and CFS could not reduce the growth of L. monocytogenes or B. thermosphacta. Concentrating preparations are important for obtaining a suitable antibacterial preparation that contributes to consumer safety and food quality when applied as a protective additive.