Studies on Efficacy of Freezing on the Reduction of Campylobacter jejuni in Chicken Meat

Abstract

Here we examined the efficacy of freezing treatment to reduce the survival of Campylobacter jejuni/coli in chicken meat. Spike experiments showed approximately 1.9–2.3 log CFU/g reduction of C. jejuni NCTC 11168 and 81–176 strains in minced chicken meats following the freezing at -20℃ for 2 weeks. This freezing condition also induced significant reduction of bacterial detection ratio in commercially-distributed minced chicken meats that exhibited 40% positivity for Campylobacter spp. as natural contamination. Furthermore, crust freezing procedure decreased numbers of Campylobacter spp. in chicken meats and offal, compared with those in chilled chicken samples, although indicator bacterial counts did not correlate with the different treatments. Qualitative detection of Campylobacter spp. resulted that imported frozen chicken thigh samples showed only 2.2% positivity while domestically-produced chilled samples were 26.7% positive for those bacteria. Together, these data clearly indicated that freezing treatment consecutively reduced survival of the thermophilic Campylobacter in chicken meats. Practical application of this treatment would be helpful to control of this pathogen in chicken meats.