Factors affecting the survival of Campylobacter jejuni in relation to immersion scalding of poultry

Potential measures for reducing the survival of campylobacters during commercial scalding of poultry have been evaluated in a series of laboratory trials. At 50 degrees C, the lower temperature limit of commercial scalding, raising the pH of a buffered heating medium from 6.0 to 9.0 markedly increased the heat sensitivity of Campylobacter jejuni but the effect was largely nullified in the presence of 1 per cent 'organic material' (50:50 horse blood and milk). Either in the presence or absence of organic material a more rapid rate of kill was observed at 60 degrees C and it was again enhanced by raising the pH to 9.0. Use of a mild detergent at a concentration of 1000 ppm had little effect on the survival of C jejuni at 50 degrees C, but the addition of a cationic quaternary ammonium product at 50 to 100 ppm was highly effective in enhancing the rate of kill, even in the presence of organic material. It is suggested that such products should be evaluated in commercial scalding systems as a possible means of preventing the spread of campylobacters and other organisms of significance to public health.