The effect of lactic acid sprays on Campylobacter jejuni inoculated onto poultry carcasses

Spraying poultry carcasses with 1% lactic acid 10 min after inoculation with Campylobacter jejuni, resulted in a significant reduction in the number of the bacteria after 4 h at 4 degrees C. Some of the inoculated cells, however, survived for at least 144 h. Spraying 10 min after inoculation with 2% lactic acid, totally eliminated all inoculated C. jejuni within 24 h. On the other hand, spraying 24 h after inoculation, with either 1% or 2% lactic acid did not eliminate all the bacteria. Inoculated C. jejuni on poultry carcasses not sprayed with lactic acid, survived at 4 degrees C throughout the sampling period (up to 144 h) and showed little tendency to decrease in number even when the carcasses started to deteriorate. Resident campylobacters on poultry carcasses were significantly reduced by the lactic acid treatment. Frozen and thawed chickens appeared to show a graying of the skins immediately after spraying with lactic acid, slightly stronger with 2% lactic acid, but the colour reverted to normal after 24 h. We were not able to observe any colour change on the fresh broiler chickens after lactic acid treatment. Our results indicated that lactic acid had a significant bactericidal effect on C. jejuni on both naturally and artificially contaminated poultry carcasses. This effect, however, became manifest only several hours after acid treatment.