Campylobacter bacteria are weakened after a hot thermal shock

Globally, Campylobacter infections are the leading cause of human bacterial enteritis. Broiler meat is considered the most common source of contamination. In order to reduce the level of Campylobacter contamination, this work studies the influence of stress conditions encountered during the slaughter of poultry on the subsequent cold inactivation of Campylobacter jejuni in products packaged under modified atmosphere.
Reproducing the conditions encountered during slaughter, three strains of C. jejuni were successively subjected to hot stress assimilated to scalding (46, 50 or 54 ° C for 4 min) and cold stress assimilated to chilling ( -4 or 3 ° C for 2 hours) by immersion in thermostated baths. The bacteria were then placed at 6 ° C for seven days in one of the two most widely used modified atmospheres for the packaging of prepackaged poultry products (70% O2 / 30% CO2 or 50% CO2 / 50% N2 ).
The inactivation of C. jejuni during refrigerated storage is significantly dependent on the temperature applied during hot stress and the modified atmosphere used during storage. It is highest in the oxygen-enriched atmosphere when C. jejuni is previously subjected to a temperature of 54 ° C. Inactivation also varies depending on the bacterial strain.
These results show that the stresses applied successively influence the future behavior of the bacteria. Thus, strategies aimed at controlling the level of C. jejuni contamination in ready-to-cook products should, in addition to preservation conditions during refrigerated storage, incorporate the thermal conditions encountered by bacteria during the poultry processing process.

Partners: This study was carried out by SECALIM, in collaboration with the Pôle Agronomique Ouest, the Laboratory of microbial biodiversity and ecoclogy (LUBEM) of Bretagne Ouest university, ADRIA Quimper and industrials.

Funding: Iinter-régional project BIOMICS funded by Régions Bretagne and Pays de la Loire