Assessment of the di- and tri-chlorinated haloacetic acids during broiler prechilling

Sodium hypochlorite (NaClO) has been widely used at 100 ppm concentration during poultry slaughter to reduce carcass microorganism loads. However, its use in poultry processing is restricted owing to the potential risks of disinfection by-products (DBPs) that can be produced by the reaction of NaClO with poultry meat components. This study assessed whether dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA), as primary DBP representatives, were produced when NaClO was used as a disinfectant in various methods during broiler prechilling. Headspace gas chromatography-mass spectrometry for the quantitative determination of DCAA and TCAA in 180 prechilling water samples and 30 broiler meat samples, obtained from large standard slaughterhouses equipped with an online monitoring system to control the NaClO concentration between 50 and 100 ppm, showed that neither DCAA nor TCAA were detected. In simulation assays, haloacetic acids (HAAs) were not detected when the concentration of the NaClO solution was less than 200 ppm with low frequency addition; however, more than 0.1 mg/L of DCAA and TCAA were detected on applying 200, 300, 400, 500, and 1000 ppm NaClO at high frequency. These findings indicated that adding high concentrations of NaClO and frequently adding low levels pose a potential risk of DBP formation. This investigation provides a basis for the establishment of food risk and the scientific use of NaClO in poultry processing, and contributes to the evaluation of DBPs in poultry slaughter. PRACTICAL APPLICATION: This study confirmed the occurrences of DCAA and TCAA during broiler chilling processing, indicating that formation of HAAs in simulation systems was correlated with NaClO levels and validated the absence of DCAA and TCAA with less than 200 ppm, providing a basic study for food safety standards and regulations on the disinfectants used in food processing.