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United States Department of Agriculture

Agricultural Research Service

Research Project: Microbial Ecology of Human Pathogens Relative to Poultry Processing Title: A chemical additive to limit potential bacterial contamination in chill tanks

item Schambach, Bradley
item Berrang, Mark
item Harrison, Mark -

Submitted to: International Poultry Scientific Forum
Publication Type: Abstract Only
Publication Acceptance Date: October 25, 2012
Publication Date: January 23, 2012
Citation: Schambach, B.T., Berrang, M.E., Harrison, M. 2012. A chemical additive to limit potential bacterial contamination in chill tanks [abstract]. International Poultry Scientific Forum. p. 3.

Technical Abstract: Broiler carcasses with different types and numbers of bacteria are commonly chilled together in an ice water bath which may lead to transfer of unwanted bacteria from carcass to carcass. Historically chill tanks have been chlorinated to help prevent cross contamination and recently other chemical additive options have become available to help lower bacterial counts during the chilling process. The objective of this study was to test the effectiveness of a proprietary chemical additive (T-128) to lower bacterial numbers in chill water and stabilize chlorine in the presence of organic material. To test this, eight containers were prepared, with each one containing one a broiler wing, water, and ice in a weight to weight ratio of 1:2:4 chicken meat to water to ice. Two containers were assigned to each of four treatments, as follows: control (no additive), 50 parts per million (ppm) chlorine, 0.5% T-128 (by volume), and a combination of 50 ppm chlorine and 0.5% T-128. All containers were covered with aluminum foil and shaken at 130 rpm for forty five minutes. Water temperature, pH, free chlorine, and total chlorine were measured at time 0 (before shaking) and after 45 min of chilling. Also at time 0 and 45 min, one mL of chill water was plated on the surface of plate count agar. Plates were incubated for 24 hours at 37°C and the resultant colonies were counted. This experiment was replicated five times resulting in a total of ten samples for each of the four treatments. After 45 minutes of shaking, the mean chill water temperature ranged from 0.6 to 0.8°C. Mean chill water pH was as follows: control: 6.92, 50ppm chlorine: 7.08, 0.5% T-128: 3.10, and 50ppm chlorine plus 0.5% T-128: 3.85. Mean free chlorine levels after 45 min were the following: control: 0.0ppm, 50 ppm chlorine: 3.01 ppm, 0.5% T-128: 0.0 ppm, and 50 ppm chlorine plus 0.5% T-128: 2.84 ppm. Mean numbers of total aerobic bacteria detected per mL of chill water after 45 min were 213 colony forming units (CFU) in the control, 107 CFU in the chlorinated samples, 8 CFU and 10 CFU in the T-128 only and T-128 plus chlorine samples respectively. Despite the fact that after 45 min, samples containing T-128 had similar levels of active chlorine as chlorinated samples without the additive, those with T-128 had significantly lower chill water plate counts. Further research is needed to determine if these results are due to T-128 interacting with chlorine or simply from the pH reduction caused by the addition of T-128 itself.

Last Modified: 6/2/2015