Effect of natural plant-derived agents on the survival of the pathogenic bacteria Salmonella spp., Listeria monocytogenes in marinated chicken liver meat

Abstract

This experimental study followed the survival (after inoculation of the bacteria) on non-marinated and marinated chicken liver meat (CLM) samples, with or without added antimicrobials (carvacrol; CA, garlic: G), stored at 4 and 10 �C for 14 days. A pomegranate pomace-based marinade (PPM) alone, or in combination with CA or G was used to monitor the survival/growth of Salmonella spp. and Listeria monocytogenes counts on CLM. A declining trend was recorded for both Salmonella spp. (4.1-4.4 and 3.8-4.3 log CFU/g) and Listeria monocytogenes (3.6-4.6 and 3.3-4.5 log CFU/g) populations in both marinated (absence of antimicrobials) and marinated (with antimicrobials) CLM samples, respectively, at 4 and 10 �C, on day 14 (final storage day). At 10�C, marination and antimicrobial treatments resulted in lower Salmonella spp and Listeria monocytogenes counts on CLM, compared to 4 �C (3.4-3.9 and 1.5-3.7 logs) in both marinated (absence of antimicrobials) and marinated (with antimicrobials) CLM samples, respectively, at 4 and 10 �C, on final day-14. Marination and combinations reduced the total plate count (TPC) by 0.3-0.9 and 0.2-0.6 log CFU/g, as compared to the control (non-marinated) in CLM samples (absence of inoculated bacteria) on final day-14. Concluding, it can be stated that a microbiological shelf-life extension of 9 and 11 days, as compared to the control's shelf-life, was achieved at 4 and 10�C, respectively. The initial pH values of the control (non-marinated) and marinated CLM samples at 4 and 10�C, were 6.62 and 3.12, respectively. During the storage period, pH values for the control CLM were found to be higher, as compared to the marinated samples, and irrespective of storage temperature.