Antimicrobial efficacy of postbiotics of lactic acid bacteria and their effects on food safety and shelf life of chicken meat
Abstract
In this study, the antibacterial effects of postbiotics obtained from Pediococcus acidilactici, Lactiplantibacillus plantarum and Latilactobacillus sakei, which were grown in sterile cow's milk and De Man Rogosa and Sharpe (MRS) Broth, against some food pathogens (Salmonella spp., Listeria monocytogenes, Escherichia coli O157:H7, and Brucella melitensis) was investigated. It was observed that lactic acid bacteria postbiotics produced in MRS Broth formed larger inhibition zones than those developed in cow's milk against pathogenic bacteria. In order to investigate the antimicrobial effect of the postbiotics on chicken breast meat and to compare this effect with lactic acid decontamination, samples contaminated with Salmonella spp. and L. monocytogenes were immersed into the postbiotics of L. plantarum and L. sakei, 2.1% lactic acid solution, and distilled water for 10 minutes. Microbial changes in the groups were investigated during the storage at 4 ? for 17 days. On the 8(th) day of storage, it was determined that the number of Salmonella spp. in the groups treated with postbiotics decreased by 0.9 log(10) CFU/g compared to the control and distilled water groups. While the number of L. monocytogenes increased during storage in the control and distilled water groups, the postbiotics and 2.1% lactic acid exhibited a bacteriostatic effect on L. monocytogenes during storage period. Compared to the postbiotics, 2.1% lactic acid had higher reduction (1.8 log(10) CFU/g) rates against Salmonella spp. (P<0.05), also a significant difference was observed against L. monocytogenes in the first and last days of storage (P<0.05). While the shelf life of chicken breast meat was determined to be 5 days in the control and distilled water groups, postbiotic treatments extended the shelf life of chicken breast meat by an extra 9 days, and %2.1 lactic acid treatment extended an extra 12 days compared to the control and distilled water treatments.