Submitted to: Poultry Science
Publication Type: Abstract Only
Publication Acceptance Date: 3/9/2004
Publication Date: 7/26/2004
Citation: Bourassa, D.V., Buhr, R.J., Fletcher, R.J., Berrang, M.E., Cason Jr, J.A. 2004. Enrichment ph does not influence salmonellae recovery from pre-chill broiler carcasses treated with tsp. [abstract] Poultry Science. 83(suppl.1):155.
Technical Abstract: Trisodium phosphate (TSP) has been shown to reduce the recovery of salmonellae from processed poultry carcasses. It has been suggested that the high pH of TSP solutions as well as the detergent-like properties are responsible for the reduction in salmonellae recovery. This project was conducted to determine the efficacy of TSP on the recovery of salmonellae when the pH of the enrichment peptone is neutralized shortly after application of TSP. For 4 consecutive wk, 40 carcasses were obtained from a commercial processing plant evisceration line after the final inside-outside carcass washer prior to chilling, individually bagged and transported to the lab. Carcasses were segregated into four treatment groups of 10 carcasses each; 1) TSP and neutral-peptone (pH 7.0), 2) TSP and acidified-peptone (pH 5.5), 3) no TSP and alkali-peptone (pH 8.5), 4) no TSP and neutral-peptone. In batches of two, half of the carcasses were immersion dipped in a 10% w/v TSP solution and allowed to drip for 1 min, while the remaining carcasses were not treated with TSP. Each carcass was then placed into a plastic bag to which 500 mL of the appropriate peptone was added, and the carcasses were shaken for 1 min. A 5 mL aliquot was removed from each bag to determine pre-incubation pH. Bagged carcasses were placed into pans and incubated aerobically at 37 C for the initiation of whole carcass enrichment detection of salmonellae. The pH of the pre-incubation enrichment peptone was 8.4 for the TSP neutral-peptone group, 7.2 for the TSP acidified-peptone group, 8.7 for the no TSP alkali-peptone group, and 7.1 for the no TSP neutral-peptone group. Salmonellae was detected from 20/40 (50%) of the TSP neutral-peptone carcasses, from 21/40 (53%) of the TSP acidified-peptone carcasses, from 25/40 (63%) of the no TSP alkali-peptone carcasses, and from 17/40 (43%) of the no TSP neutral-peptone carcasses. Dipping pre-chill carcasses in TSP, or the acidification or alkalisation of the peptone enrichment broth did not significantly alter the recovery of salmonellae as determined by whole carcass enrichment (52%, 83/160 carcasses). Key Words: trisodium phosphate, salmonellae, pH, broilers, pre-chill