Surface contamination of beef carcasses by fecal coliforms

Abstract

A total of 18 half-carcasses was selected at random in each of three different meat processing establishments. Samples were taken by excision at seven sites on each half-carcass at the end of four processing sectors, from the dressing of the carcass to the packaging of boneless beef, and the fecal coliform counts per cm2 were subsequently determined. A statistically significant difference in mean fecal coliform count was found between the reference and the other two establishments. Among the four processing steps, boning operations contributed the most to the final count of fecal coliforms on boneless beef. Generally speaking, among the sites, the flank recorded the highest mean fecal coliform count per cm2; nonetheless, following boning operations, the semitendinosus area demonstrated a mean count significantly higher than all the other sites, with the sole exception of the rump. No consistent differences in mean fecal coliform counts were found between the days or the times of sampling, nor between the front and hind quarters. No meaningful linear correlation was detected between the fecal coliform counts and the factors under study, i.e., length of time a carcass is kept in the evisceration area, relative humidity of the evisceration area, warm carcass weight, duration of cold storage, and temperature and relative humidity of the boning room. In summary, the results indicate that any attempt at successfully minimizing boneless beef contamination by fecal coliforms requires the application of tighter control over cross-contamination at the boning room level.