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Title: Effect of immersion or dry air chilling on bacteria recovery from broiler carcasses

Author
item HUEZO, R - UGA
item Northcutt, Julie
item Smith, Douglas
item FLETCHER, DANIEL - UCONN
item Ingram, Kimberly

Submitted to: Journal of Food Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/24/2007
Publication Date: 8/6/2007
Citation: Huezo, R., Northcutt, J.K., Smith, D.P., Fletcher, D.L., Ingram, K.D. 2007. Effect of dry air and immersion chilling on bacteria recovery from broiler carcasses. Journal of Food Protection. 70:1829-1834.

Interpretive Summary: Effect of Immersion or Dry Air Chilling on Bacteria Recovery from Broiler Carcasses R. Huezo* J. K. Northcutt†, D. P. Smith†, D. L. Fletcher††, and K. D. Ingram† *The University of Georgia, Athens, GA 30605, †USDA, Agricultural Research Service, Athens, GA 30604-5677, ††University of Connecticut, Storrs, CT 06269-4040 A study was conducted to investigate the effect of chilling method (air and immersion) on bacteria recovery from broiler carcasses. Live broilers were given a suspension containing bacteria. After a holding period, broilers were processed and the carcasses were cooled by tradition immersion chilling in ice water or by dry air. Overall, both chilling methods significantly reduced bacteria levels on the carcasses. No difference was observed in carcass bacteria counts between the two chilling methods. Air and immersion chilling reduced E. coli and coliforms levels by 90% as compared to non-chilled carcasses. Carcass chilling method had no effect on the number of Campylobacter and Salmonella or the prevalence of Campylobacter and Salmonella. However, post chill carcass counts of Campylobacter and Salmonella were significantly lower than the prechill carcass counts. These results demonstrate that air and immersion chilled carcasses, without any chemical intervention, are microbiologically comparable, and a 90% reduction in counts of bacteria can be obtained after chilling.

Technical Abstract: A study was conducted to investigate the effect of chilling method (air and immersion) on Escherichia coli, coliforms, Campylobacter, and Salmonellae counts and prevalence recovered from broiler carcasses. During each of four replications, 60 broilers were inoculated orally and intra-cloacally with 1 mL of a suspension containing approximately 108 cells/mL of Campylobacter. After one day, broilers were inoculated with 1 mL of a suspension containing approximately 108 cells/mL of Salmonella. Broilers were processed and carcasses were cooled by dry air (3.5 m/s, -1.1o C, 150 min) or immersion chilling in ice water (0.6o C, 50 min). Pre-chill counts recovered from carcasses averaged 3.5, 3.7, 3.4, and 1.4 log10 cfu/mL of rinse for E. coli, coliforms, Campylobacter, and Salmonella, respectively. Overall, both chilling methods significantly reduced bacteria levels on the carcasses, and no difference in the bacteria counts was observed between the two chilling methods (P < 0.05). Both chilling methods reduced E. coli and coliforms levels by 0.9 to 1.0 log units. Chilling reduced Campylobacter levels by 1.4 log (air) and 1.0 log (immersion), while Salmonella reductions were 1.0 log and 0.6 log units for air and immersion chilling, respectively. Chilling method had no effect on the prevalence of Campylobacter and Salmonella recovered form carcasses. These results demonstrate that air and immersion chilled carcasses, without any chemical intervention, are microbiologically comparable, and a 90% reduction in counts of E. coli, coliforms, and Campylobacter can be obtained after chilling.