Destruction of Escherichia coli and salmonellae on mutton carcases by treatment with hot water

Abstract

Laboratory experiments showed that the surface tissues of beef and mutton samples were not permanently discoloured to an objectionable extent by treatment with water at 80° C or 10 sec. This treatment destroyed more than 99% of the numbers of E. coli and salmonellae inoculated on the beef samples and more than 99·9% of the same organisms inoculated on the exterior surfaces of tissue taken from sheep carcases. Immersion in water at 80°C for 10 sec of whole sheep carcases taken off the end of the slaughter line in a commercial abattoir destroyed c. 99% of the contaminating coliform organisms and c. 96% of the total number of aerobic bacteria initially present on the surface tissues. The application of such a treatment to sheep carcases in abattoirs should substantially reduce any salmonella contamination on the meat and may improve storage life. Although initially discoloured to a depth of 0·5 mm by the treatment, sheep carcases heated at 80°C for 10 sec almost completely regained their normal appearance within a few hours during subsequent chilled storage at 1–4°C.