Can chemical decontamination reduce germ counts in poultry meat?

The prevalence of pathogens such as Salmonella or Campylobacter spp. poses a health risk to consumers. In recent years, for example, the Robert Koch Institute (RKI) has recorded between 40,000 and 50,000 annual cases of Campylobacter infections in Germany (https://survstat.rki.de).

Illness cases can often be traced back to the consumption of contaminated poultry meat. Based on data from previous studies, the European Food Safety Authority (EFSAshort forEuropean Food Safety Authority) determined that approximately 20 to 30 % of human campylobacteriosis cases in 2010 were attributable to the consumption of poultry meat.

The requirements of Regulation (EC) No 2073/2005 on microbiological criteria for foodstuffs also apply to poultry meat. This regulation includes a food safety criterion for the Salmonella serotypes Salmonella Enteritidis and Typhimurium, which, when testing a sample size of n=5, may not be present in 25 grams of the tested meat.

In order to reduce the high number of cases of illness in humans caused by infection with the bacterium, a process hygiene criterion for Campylobacter spp. was also introduced at the EU-level in 2018. This is intended to help ensure that poultry meat with high levels of Campylobacter per gram of meat becomes increasingly rare on the market. However, if high concentrations of Campylobacter (more than 1,000 colonies per gram of neck skin sample after cooling in 10 out of 50 samples over 10 weeks) are detected, the food business operator is obliged to improve hygiene.

Food companies are already required to carry out the slaughtering process under the best possible hygienic conditions.

Several strategies are currently being pursued to combat pathogenic microorganisms in and on poultry meat. These include:

• the utmost care in the rearing and fattening of poultry,
• hygienic conditions during all stages of slaughter,
• rapid and effective cooling,
• targeted cleaning and disinfection of slaughtering machinery and equipment that comes into contact with the product.

In recent years, targeted research, including with the involvement of the BfRshort forGerman Federal Institute for Risk Assessment, has been conducted to refine these strategies (see "Further information on research into the hygienic handling of poultry meat" below).

"Chemical decontamination" of food refers to the use of antimicrobial substances such as chlorine dioxide or peroxyacetic acid in order to reduce the bacterial content of Salmonella or Campylobacter.

Hygiene measures taken to date have not been sufficient to reduce the prevalence of Campylobacter spp. in poultry meat in particular. However, consumers generally expect food to be safe and not pose a health risk. Kitchen hygiene measures to protect against foodborne infections in the home do not seem to be sufficiently observed, as the vast majority of cases are acquired there.

For instance, statistics from the European Food Safety Authority (EFSAshort forEuropean Food Safety Authority) and the European Centre for Disease Prevention and Control (ECDCshort forEuropean Centre for Disease Prevention and Control) show that almost 150,000 cases of human campylobacteriosis were reported in the EU in 2023. 24% of reported cases required hospital treatment (see "Further information on research into the hygienic handling of poultry meat" below: The European Union One Health 2023 Zoonoses report, FSA Journal 2024).

Currently, removing surface contamination from poultry meat may only be performed using drinking water. Decontamination agents are not yet permitted for poultry meat.

More than 20 years ago, the EU Commission proposed allowing the use of peroxyacetic acid for the decontamination of poultry meat as an additional measure to improve poultry meat hygiene under certain conditions.

In order to prevent resistant germs and the formation of residues, the EU proposal also specifies appropriate concentrations and exposureClose dialogexposureExposureTo glossary times for the use of peroxyacetic acid and sets control parameters that food businesses must use to monitor the hygiene and decontamination measures they have taken.

However, the EU proposal particularly emphasises the importance of hygiene measures in poultry meat production. As part of a hurdle concept, these hygiene measures remain of paramount importance and cannot be replaced by decontamination measures. Instead, conventional hygiene requirements and options should be combined with an additional decontamination process throughout the entire rearing, fattening, transport and slaughtering process. However, the European Union has not yet decided to introduce chemical decontamination of poultry meat.

Laying down specific hygiene rules for food of animal origin, Regulation (EC) No 853/2004 stipulates that, apart from drinking water, only substances approved by the European Commission may be used to remove surface contamination. In the EU, only lactic acid is approved as a decontamination agent for use on beef half-carcasses.

In principle, toxicological assessments of decontamination agents for meat are carried out in the same way as for processing aids, food additives or biocides, which also include disinfectants and decontamination agents.

However, different and more specific testing requirements and evaluation criteria apply to these substances. The European Food Safety Authority (EFSAshort forEuropean Food Safety Authority) has published guidance on evaluation criteria for decontamination agents (External Link:http://www.efsa.europa.eu/sites/default/files/scientific_output/files/main_documents/1544.pdf).

In 2014, the European Food Safety Authority (EFSAshort forEuropean Food Safety Authority) looked at the decontamination of poultry meat. It assessed the safety and efficacyClose dialogefficacyPositive Predictive ValueTo glossary of peroxyacetic acid as a decontamination agent and concluded that the process is a suitable additional means of reducing pathogens. From a toxicological point of view, the use of peroxyacetic acid to reduce the bacterial load on poultry meat is not expected to pose a health risk to consumers (see "Further information on research into the hygienic handling of poultry meat" below: EFSAshort forEuropean Food Safety Authority BIOHAZ Panel (EFSAshort forEuropean Food Safety Authority Panel on Biological Hazards), EFSAshort forEuropean Food Safety Authority Journal 2014).

The ideal decontamination agent must have a broad spectrum of activity or a high selective effect against bacteria.

The ideal decontamination agent should have a rapid and irreversible effect in the dilution used and show little loss of effectiveness due to environmental influences (e.g. protein, pH or temperature). Furthermore, the agent should no longer be present in the food at the time of consumption. It should also not have any negative effects on the surface of the food and have good application properties.

The development of bacterial resistance to substances used for decontamination and disinfection is viewed critically. Not only must the development of resistance to the substance in question be taken into account, but also the risk that the pathogenic bacteria may also become resistant to certain antibiotics (cross-resistance).

In order to prevent the development of bacterial resistance to peroxyacetic acid, the EU proposal for the use of this substance for decontamination specifies the necessary concentrations and exposure times and, within the framework of company self-monitoring systems, sets parameters that food companies are required to monitor (see "Further information on research into the hygienic handling of poultry meat" below: EFSAshort forEuropean Food Safety Authority BIOHAZ Panel (EFSAshort forEuropean Food Safety Authority Panel on Biological Hazards), EFSAshort forEuropean Food Safety Authority Journal 2014).

Depending on the substance used, the application of decontamination procedures can result in the desired hygienic effects as well as various sensory quality deviations such as changes in colour, flavour and texture. The intended use of the treated meat is decisive for the acceptance of such deviations. The colour changes described in decontamination measures are determined by the process itself and the meat components (muscle, fat, tendons, etc.). Muscle tissue, for example, may turn grey, fade or take on brownish colour variations after treatment. The flavour may also change under the influence of decontamination agents. Although the reduced (spoilage) bacterial flora may lead to a longer shelf life due to the delayed onset of bacterial spoilage, the fat may also become rancid more quickly as a result of oxidation processes.

However, the BfRshort forGerman Federal Institute for Risk Assessment is not yet aware of any study results on sensory changes in poultry meat following treatment with peroxyacetic acid.

In the BfR’s view, the sole use of chemical substances to obtain "low-germ" food is not sufficient to improve food safety. Chemical decontamination could be another component in a series of necessary measures (hurdle concept), starting with good hygiene in poultry flocks and in slaughterhouses with the aim of minimising pathogenic contamination.

An important prerequisite for the use of decontamination agents is that they must be safe for human health. The BfRshort forGerman Federal Institute for Risk Assessment is conducting research into this and assessing possible health risks.

This text version is a translation of the original German text which is the only legally binding version.