Trimming and Washing Poultry Carcasses to Reduce Microbial Contamination

Washing chicken carcasses with water containing a low level of chlorine was effective in reducing counts of aerobic bacteria, total coliforms and E.coli, according to a new study from Brazil. Trimming was less effective.

19 December 2014

3 minute read

By: Jackie Linden

In the current issue of Poultry Science, researchers in Brazil report their work, which aimed to compare the efficiency of washing and trimming broiler carcasses to reduce bacterial contamination.

Lenita Moura Stefani of the University of the State of Santa Catarina and co-authors there and at the State University of Sao Paulo (UNESP) explain that, at the post-evisceration stage, they collected 100 broiler carcasses during four visits to a slaughterhouse in Santa Catarina State, Brazil.

Birds were from the same flock, age and approximately 2.4kg of weight.

The groups were as follows:

Group 1, with faecal contamination
Group 2, without faecal contamination
Group 3 with faecal contamination and trimmed
Group 4, with faecal contamination and washed and
Group 5, with faecal contamination, washed and trimmed.

Carcass washings were performed with at least 1.5 litres per bird of potable water (0.5 to 1mg per kg of residual chlorine) at room temperature (20 to 25°C) using spray cabinets with 44 spray nozzles distributed into two chambers (pressure of 2kgf per square centimetre and 4 kgf per square centimetre).

Washed carcasses (trimmed or not) showed significantly (P<0.05) lower counts of aerobic mesophiles (plate count agar) on the third evaluation, and even lower (P<0.01) counts for total coliforms (CT) and faecal coliforms (Escherichia coli).

Trimmed carcasses had significantly lower counts (P<0.05) for plate count agar; however, the researchers observed higher counts for E. coli (P<0.05).

The association of both treatments (washing and trimming) showed significantly higher (P<0.05) counts for coliforms, both in total and E. coli.

Stefani and co-authors conclude that washing is overall more efficient than trimming as a means to decontaminate chicken carcasses at the post-evisceration stage.

They add that their findings may help poultry companies to minimise production costs by applying the washing method for carcass decontamination.

Reference

Stefani L.M., R.G. Backes, G.A. Faria, C.P. Biffi, J.M. de Almeida, H.K. da Silva, G.B. das Neves and A. Langaro. 2014. Trimming and washing poultry carcass to reduce microbial contamination: a comparative study. Poultry Science. 93 12):3119-3122. doi: 10.3382/ps.2013-03383