Application of antimicrobial treatment to whole carcasses during pre-chill can improve microbial quality of broiler parts

Authors: STEININGER, CHARLOTTE - University Of Georgia; HARRISON, MARK - University Of Georgia; Berrang, Mark

Submitted to: Food Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/6/2017
Publication Date: 1/13/2018
Citation: Steininger, C., Harrison, M., Berrang, M.E. 2018. Application of antimicrobial treatment to whole carcasses during pre-chill can improve microbial quality of broiler parts. Food Microbiology. doi.org/10.1111/jfs.12434.
DOI: https://doi.org/10.1111/jfs.12434

Interpretive Summary: Campylobacter and Salmonella are pathogenic bacteria that are associated with broilers and broiler parts. Interestingly, cut-up parts have a higher prevalence of these pathogens than do whole broiler carcasses. During the pre-chill step of broiler processing, eviscerated carcasses are cooled in unchilled water to begin the chilling process and allow uptake of water. It is possible that water uptake could include bacteria which are released upon cut-up. We tested using sanitizers in the pre-chill tank as a means to lessen bacterial contamination of broiler carcasses after pre-chill, final chill and cut-up. Pre-chill treatments included 50 ppm chlorine with or without 0.5% T-128 (a chlorine stabilizer), 20 ppm peracetic acid with or without 0.5% T-128, 0.5% T-128 alone, and water control. Addition of T-128 to either sanitizer resulted in significantly lower numbers of E. coli and total bacteria on carcasses but did not affect numbers of specific pathogens, Salmonella and Campylobacter. Counts were not higher after cut-up. Application of sanitizers during pre-chill can be helpful to control bacterial contamination of processed broilers. Bacteria taken up during pre-chill are not likely the reason for higher prevalence of pathogens after cut-up compared to whole carcasses.

Technical Abstract: Increased numbers of pathogenic microorganisms on chicken parts when compared to whole broilers has led to the hypothesis that water retained during the pre-chill stage of processing harbors bacteria that contaminates parts upon cut-up. The objective of this study was to determine the effectiveness of applying an antimicrobial treatment in the pre-chill tank to reduce the prevalence or numbers of E. coli, Campylobacter, and Salmonella on chicken parts. Commercially eviscerated broiler carcasses were subjected to sequential pre-chill, chill, and cut-up procedures. Selective enrichment and isolation of Campylobacter spp. and Salmonella spp., as well as enumeration of total aerobic bacteria and E. coli/coliforms, was performed using carcass rinses at post-evisceration, after 15 min pre-chill (22-25oC water), after 30 min immersion chill (0-4oC water), and following cut-up into parts. Six pre-chill, antimicrobial treatments were evaluated: 50 ppm chlorine, 50 ppm chlorine+0.5% T-128 (a chlorine stabilizer), 20 ppm peracetic acid, 20 ppm peracetic acid+0.5% T-128, 0.5% T-128, and water. Addition of 0.5% T-128 to water, 20 ppm peracetic acid, or 50 ppm chlorine during pre-chill significantly (p<0.05) decreased total aerobic bacteria and E. coli/coliforms following pre-chill by ~1.5-2.0 log compared to the water control. No trends were observed for Salmonella or Campylobacter for any treatment.