Freezing as an intervention to reduce the numbers of campylobacters isolated from chicken livers: Campylobacters in frozen chicken livers

The aims of this study were (i) to determine the prevalence and numbers of
campylobacters in 63 samples of raw livers purchased at retail across the UK
and (ii) to investigate whether the freezing of chicken livers contaminated with
Campylobacter was a reliable method for decontamination. Chicken livers
naturally contaminated with campylobacters were subjected to freezing at 15
and 25°C for one day and 7 days. Numbers of campylobacters on the livers
were determined immediately before and after a 24-h or 7-days freeze
treatment and daily during 3 days post-thaw refrigerated storage. Freezing for
24 h at 25°C can reduce numbers of Campylobacter by up to 2 log10
CFU g
1. Freezing the livers for 24 h at 25°C, thawing overnight in a fridge
set to 4°C and refreezing for another 24 h at 25°C reduced the numbers of
campylobacters by up to three logs. Reduction in the numbers of
campylobacters was significantly greater following a second freeze treatment
compared with a single freeze treatment.