Combining antimicrobial substances for Campylobacter post harvest mitigation on chicken breast fillet and chicken skin - any synergistic effects?

Abstract

To reduce Campylobacter along the food chain, we investigated the mitigation potential of four antimicrobial compounds against Campylobacter using a new evaluation scheme. Using the checkerboard method, the minimum inhibitory concentration (MIC) values of two organic acids (peroxyacetic acid and lactic acid) and two plant extracts (carvacrol and resveratrol) against a C. jejuni and a C. coli field isolate were determined as well as the fractional inhibitory concentration (FIC) indices of combined treatment. The lowest MIC values were found for peroxyacetic acid (0.03mg mL-1) and carvacrol (0.06mg mL-1). Based on subsequent sensory studies, peroxyacetic acid and carvacrol were selected for challenge tests to quantitatively determine the reducing potential against Campylobacter on chicken meat and chicken skin. Applying peroxyacetic acid significantly reduced Campylobacter counts on chicken skin with maximum reductions of 3.3 log-units (P<.0001), while the combination of peroxyacetic acid and carvacrol resulted in significant reductions of only 0.4 log-units on chicken breast fillet 24 hours after treatment but not thereafter (P=.0192). Peroxyacetic acid is suitable as a postharvest intervention measure to reduce Campylobacter concentration on chicken skin without reducing consumer acceptance.