The effect of the final wash location on the microbiological and visual condition of lamb carcases

This project assessed the effect of washing carcases prior to the final inspection station on the microbiological and visual condition of the lamb carcase.

The project monitored prevalence and concentration of indicator bacteria (Aerobic Plate Count, E. coli and Enterobacteriaceae.) plus the frequency, amount and type of visual contamination requiring trimming in the two systems under investigation.

As part of the project, a trial was undertaken at a sheep and lamb processing plant. Carcases were assessed visually for defects by quality assurance staff when they were used as trimmers. Trimmed tissue was collected, separately for washable and not washable defects, in containers for weighing. After each monitoring period, trim from all carcase areas was weighed for all carcases. 

The trial found that: 
•    Most of the defects were on the channel and leg areas of the carcase 
•    On average, the trim weight was 20 grams less per lamb carcases and 25 grams less per sheep carcase under the alternative system. 
•    Spray-chilled carcases had higher E. coli prevalence compared with air-chilled carcases.