Peracetic acid reduces Campylobacter spp. numbers and total viable counts on broiler breast muscle and drumstick skins during modified atmosphere package storage
Constant high case numbers of human campylobacteriosis over the last few years show the necessity of efficient strategies to reduce the number of diseases. The aim of this study was to assess the effectiveness of peracetic acid (PAA) as spray application to reduce Campylobacter spp. on chicken meat. For this, the minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of 25 Campylobacter jejuni and C. coli isolates were determined. All tested isolates had MICs ranging between 2 to 8 ppm PAA, while MBCs were 1- to 4-fold higher than the MIC. An additional time-kill test, using strain C. jejuni DSM 4688, revealed that after an incubation time of 2 h in medium, supplemented with 1-fold the MIC (4 ppm) of PAA, no surviving C. jejuni cells were detectable. For evaluation of a spraying treatment, C. jejuni DSM 4688 (108 cfu/mL) inoculated chicken drumsticks and native skin-on breast fillets were treated for 30 s with PAA of 1,200 ppm concentration. Samples were packaged in modified atmosphere packages and stored at 4°C until further analysis. On day 1, 6, and 12, the fillets were used for microbial (total viable count), sensory, and physicochemical (color, pH, electrical conductivity) analysis and meat samples for myoglobin redox forms and antioxidant activity were taken. A significant reduction of the total viable counts was seen on day 6 and 12 in comparison to the water control and to the untreated fillets, respectively. Campylobacter jejuni counts on the drumsticks were significantly reduced by PAA application on day 6 and 12 in comparison to the water treatment. Except on day 12, where PAA-treated fillets showed a slightly higher percentage of oxymyoglobin, no significant differences could be found in the sensory and physicochemical measurements as well as in myoglobin and antioxidant activity. Spray application of 1,200 ppm PAA to Campylobacter-contaminated chicken samples led to a significant reduction up to 1.1 log10 of Campylobacter spp. counts without influencing chemical and sensory meat quality parameters.