Growth of Yersinia enterocolitica O:3 on modified atmosphere packaged lamb

Abstract

The growth of pathogenic Yersinia enterocolitica serotype 0:3 was investigated on lamb pieces and lamb mince, packaged in air and a range of modified atmospheres, at 5 or 0° C. The modified atmospheres investigated were: (i) vacuum pack; (ii) 80% O 2 /20% CO 2 ; (iii) 50% CO 2 /50% N 2 ; and (iv) 100% CO 2 . Y. enterocolitica 0:3 counts were examined at 28 days in each of the atmosphere/temperature combinations. Growth of Y. enterocolitica 0:3 occurred on lamb pieces stored at 5° C in air and all the modified atmospheres tested. On lamb pieces stored at 0° C, pathogen growth was noted in air, vacuum packs and 50% CO 2 /50% N 2 . In all atmospheres except air, growth of Y. enterocolitica 0:3 on minced lamb at 5 and 0° C was reduced compared to growth on lamb pieces. At 5° C on minced lamb, growth of the organism occurred in air, vacuum packs and 50% CO 2 /50% N 2 . However, at 0° C, growth was observed in air only. An atmosphere containing a high O 2 concentration was inhibitory to the growth of Y. enterocolitica 0:3. In addition, the combination of a high CO 2 (100%) atmosphere and low temperature (0° C) was inhibitory to growth.