Evaluation of an Automated Beef Carcass Washing and Sanitizing System under Production Conditions1,2

Beef half carcasses were hand- or machine-washed and then machine-sanitized with 1.5% acetic acid. Sanitizer was applied at 14.4 or 52°C. Counts of Escherichia coli, Enterobacteriaceae and aerobic bacteria, made on samples collected by excision of tissues before and after treatments, demonstrated that machine washing and sanitizing reduced counts more than did hand washing. Counts were reduced more by hot than cool acetic acid. Percentages of samples with counts of log10 5.0/200 cm2 or higher after treatment were 26 and 46 for samples from carcasses sanitized with 1.5% acetic acid at 52 and 14.4°C, respectively. After hand washings 65% of the samples had these high counts.