ASSESSMENT OF THE HYGIENIC EFFICIENCIES OF 2 COMMERCIAL PROCESSES FOR COOLING PIG CARCASS

Temperature histories were collected from random samples of pig carcasses passing through two commercial carcass cooling processes: from the deep leg area; and from the site on carcass surfaces that remains at the highest temperature for the longest period. The surface temperature history data were integrated with respect to models describing the dependency on temperature of the rates of growth of Escherichia coli and psychrotrophic pseudomonads. The sample of carcasses subjected to a freezing air blast before conventional chilling gave sets of data for final deep temperatures, calculated proliferation values for E. coli, and calculated proliferation values for pseudomonads that were distributed over lower and narrower ranges than the equivalent sets of data for the sample of carcasses passing through a wholly conventional chilling process. Those findings indicate that, under commercial circumstances, exposing carcasses to a freezing air blast before conventional chilling is likely to substantially improve the hygiene efficiency of a carcass chilling process. © 1992 Academic Press Limited.