Reducing microbial counts on chicken and turkey carcasses using lactic acid

A 4% concentration of lactic acid, buffered to pH = 3.7, was applied by spraying directly after the inside-outside washer of a commercial chicken and a turkey production line with the aim of reducing microbial counts on the carcasses. Slight paling of the skin and slight greying of the leaf fat was observed on the carcasses but this was considered to be commercially acceptable. Microbial reductions varied with length of storage after killing, and after treatment with acid. For both chicken and turkey, there was a highly significant difference (p < 0.001) in aerobic plate counts between control and treated carcasses up to Day 9, but no difference on Days 13 and 16. The largest difference between the aerobic plate counts on control and treated carcasses was 2.1 log₁₀ cfu/g on chicken (Day 6) and 1.1 log₁₀ cfu/g on turkey (Day 9). The prevalence of Campylobacter on turkey carcasses on the day after slaughter was reduced significantly (p < 0.001) by the application of the acid. The results indicate that the application of lactic acid offers a method of reducing microbial counts on poultry and may have implications for shelf life and food safety.