Control of microbial contamination in provincially licensed meat plants
Learn about required microbial control interventions and best practices to control microbial contamination.
Mandatory implementation of microbial control interventions in provincially licensed abattoirs
Food safety is a priority for Ontario. To help strengthen Ontario’s food safety system, the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) implemented the mandatory use of microbial control interventions in all provincially licensed abattoirs.
Combined with control measures already in place in abattoirs, the use of a microbial control intervention is an additional precaution to make slaughter and processing even safer.
Microbial control interventions are treatments applied to carcasses both during and at the end of dressing to effectively remove or inactivate bacterial contamination and improve meat safety.
Each provincially licensed abattoir must have a microbial control intervention in place. Operators have a range of microbial control intervention options to choose from, which have no impact on quality or taste and are completely safe for consumers.
Commonly used microbial control interventions include:
- organic acid rinses
- hot water rinses
- steam pasteurization
- steam vacuuming
- dry aging
For more information on implementing microbial control interventions, please see Meat Plant Guideline Reference No.: S9.08.13.02 Microbial control interventions for red meat species and poultry.
Implementing microbial control interventions on beef and veal in provincially licensed plants
Introduction
Escherichia coli (E. coli) bacteria normally live in human and animal intestines. Most E. coli are harmless and are an important part of a healthy human intestinal function. However, some E. coli are pathogenic, meaning they can cause illness.
Pathogenic E. coli cause disease by making a toxin called Shiga toxin. The type of E. coli that make these toxins are called "Shiga toxin-producing" E. coli, or STEC for short. STEC cause human illnesses, which can range from mild diarrhea to very severe and life-threatening conditions, including death.
The STEC strain most frequently associated with human illness in North America is serotype O157:H7. However, other E. coli serotypes (O26, O45, O111, O103, O121, and O145) are also commonly associated with severe illness in humans, and there are more as well.
Contamination risks
Contamination of meat during slaughter and processing is a major risk for subsequent food-borne illnesses in humans. This is because bacteria can be transferred from the fecal material, gastrointestinal tract, hide and plant equipment to the carcass during processing.
This contamination is very difficult to prevent. There is no substitute for keeping bacteria off the carcass in the first place, but microbial carcass interventions can be used to further reduce the presence of E. coli on the carcass.
Microbial control intervention
Microbial control interventions are biological or chemical processes or agents, usually applied to the surface of the meat, to adequately inhibit, reduce or kill micro-organisms.
Applying microbial control interventions to carcasses during or after the dressing procedure is important to effectively remove or inactivate bacterial contamination and improve meat safety.
See the Appendix for a list of microbial control interventions and implementation guidelines.
Best practices
Choose the most appropriate microbial control intervention for your operation that will reduce the presence of contaminating E. coli. The type of microbial control intervention you choose will depend on the effectiveness of the intervention in the setting it is used in, the method of application and the cost.
Make sure that carcasses are as clean as possible using hygienic slaughter practices and proper carcass washing before the intervention application.
The ideal location to apply microbial interventions is after the final carcass wash because this is the last step during processing before chilling, although they can be applied at various control points during dressing for improved control of contamination. Trimming removes visible contamination, whereas microbial control interventions are effective in removing bacterial contamination that may not be visible.
Peroxyacetic acid, lactic acid, acetic acid or other organic acid rinses
Peroxyacetic/peracetic acid (PAA) must only be mixed with water at ambient temperature or up to 20°C and must not be applied at a concentration of greater than 2000 ppm.
Lactic acid is most effective when it is mixed and applied at up to 10.0%, with warm water (up to 54.5°C/130°F). The most common applied level of lactic acid on carcasses being marketed whole is 5.0%, with no rinse required.
Acetic acid is most effective when it is mixed and applied at up to 5.0%, with a warm solution temperature (up to 54.5°C/130°F).
Citric acid is most effective when it is mixed and applied at up to 5.0%, with warm water (up to 54.5°C/130°F). No rinse is required.
Best practices
Regardless of the acid used, two thorough passes should be made over the entire carcass surface with a hose or garden type sprayer approved for use in a food establishment.
Carcass should be thoroughly washed with warm water (preferable) and allowed to drip for a minimum five minutes prior to applying an acid wash. This ensures any acid intervention applied to the carcass is not diluted by the warm water wash. Ensure that the acid solution is at the proper concentration and document the concentration of the solution when it is made and when the acid intervention is applied to the carcasses. Testing kits available from your chemical supplier, can be used to test the concentration of the acid solution to ensure it is meeting requirements and will be effective when applied.
Wear proper personal protective equipment (PPE) when mixing and spraying chemicals.
Ensure Safety Data Sheets are accessible to all workers.
Application of chemicals to bovine carcasses must follow manufacturer’s requirements. Intervention options that rely on chemicals should have supplier or manufacturer documentation that indicates the expiry or best before date accompanying the product. This is because chemicals are subject to denaturing or degradation over time, therefore expired chemicals or chemicals past their best before date should not be used. Operators are responsible to ensure that interventions are applied in effective concentrations.
Operators should include expiry dates of source material and date of mixing.
Appendix
| Microbial control intervention | Implementation guidance | Suggested record keeping |
|---|---|---|
| Hot water | Minimum 74°C (165°F) for 5 seconds |
|
| Hot water wash cabinet | As per manufacturer’s instructions, water temperature minimum 74°C (165°F) for 5 seconds |
|
| Steam pasteurization | As per manufacturer’s instructions |
|
| Steam vacuuming | As per manufacturer’s instructions, steam is delivered by a continuous stream of 7-10 psi water at 82-94°C while simultaneously vacuuming the area around the stream of hot water |
|
| Peroxyacetic/peracetic acid (PAA) | Not greater than 2000 ppm |
|
| Acetic acid | 5.0% applied with warm water (up to 54.5°C/130°F) |
|
| Lactic acid | Up to 10% applied with warm water (up to 54.5°C/130°F) |
|
| Citric acid | 5.0% applied with warm water (up to 54.5°C/130°F) |
|
| Sodium hypochlorite | Not greater than 20ppm, followed by a potable water rinse |
|
| Dry aging | No more than 90% relative humidity, temperature of 4°C or less for at least 6 days |
|
| Any other microbial control intervention that is effective in reducing carcass microbial loads. | Scientifically validated by the operator and submitted for review and approval by the Food Safety Inspection Delivery Branch. | |
Best management practices to control microbial contamination in provincially licensed poultry abattoirs
Introduction
The bacteria Salmonella and Campylobacter are major causes of foodborne illness in humans. They are frequently transmitted to people through the consumption of contaminated foods derived from animals, especially poultry products.
Studies have shown significant reduction in contamination by these bacteria can be readily accomplished with the use of a few simple best management practices and the implementation of a microbial control intervention.
In addition to reducing the risk of foodborne illnesses, reductions in microbial loading can also increase the shelf-life of poultry products as spoilage of chicken meat is due primarily to bacterial growth on the surface of the bird.
Study findings
OMAFRA conducted two studies to assess bacterial contamination in provincially licensed poultry abattoirs and develop recommendations to reduce contamination.
Poultry baseline study
From December 2009 to January 2011, OMAFRA collected more than 1600 carcass rinse samples from broiler chickens (less than 2.2 kg) and tested them for pathogens and indicator organisms.
The study found that, on average:
- 38% of broiler carcasses were positive for Salmonella
- 43% were positive for Campylobacter
- 14% were positive for Listeria monocytogenes
Microbiological poultry chill system performance study
In 2014, OMAFRA staff evaluated best management practices, plant sanitation and chemical interventions on chilling systems in provincially licensed poultry abattoirs as means of controlling pathogen loading onto poultry carcasses.
Best management practices
Generally, operators can improve the microbial quality of carcasses in their plants through the following practices to control contamination:
- changing chill tank practices and air chill handling
- improving evisceration
- changing defeathering and scalding practices
- ensure correct plant sanitation practices
- monitor staff performance
More specific best management practices that can lead to significant improvements in provincially licensed poultry abattoirs with respect to microbiological contamination in chilling systems are outlined below.
Inside/Outside (I/O) wash
During the baseline study, common issues observed with I/O washes included:
- inefficient use of water due to jets improperly aimed at the carcasses
- insufficient water pressure to have a desired washing impact
These issues can lead to heavy loading of organics (blood, fecal material), pathogens and spoilage organisms into the immersion chilling systems. This loading leads to cross-contamination and organic burden during the chilling process.
Results of indicator organism counts (ACC, coliforms, E. coli and spoilage organisms) showed that most plants have very high contamination before the I/O wash, and that the I/O wash can reduce organic loading and bacterial counts when water is used at the right temperature, at high enough water pressure and with properly aimed water jets on the carcass.
Immersion chilling
Without adequate chemical intervention in chill tanks, microbiological contamination in the tanks increases quickly to very high levels, which results in an increase in the counts of microorganisms on all carcasses that enter the chilling system.
Once untreated water in chill tanks becomes positive for pathogens, such as Salmonella and Campylobacter, and spoilage organisms, it remains positive for the duration of the slaughter day and most carcasses that exit the chilling system are also positive for the presence of these pathogens.
Best practices
Effectively clean and sanitize chill tank systems daily to prevent the development of biofilms and pathogen loading that will contaminate future processing days’ product.
Ensure poultry chill tanks overflow water so that fresh water is added throughout the processing day in a countercurrent flow direction. This allows the most contaminated water to exit the tank at the end where unwashed carcasses enter.
Plants that chill carcasses in smaller bins (or containers) with ice and water should completely drain and sanitize the system prior to re-use. If rinsing and sanitation are not completed between each bin use, there is a high rate of cross-contamination from the first batch chilled to subsequent batches, thus decreasing the microbiological safety and quality of the product. Changing water in chilling systems is a critical step in not only reducing microbiological cross-contamination but also organic loading (blood, fecal material, etc.) that hinders the chemical intervention.
Chapter 19 of the Canadian Food Inspection Agency (CFIA) Manual of Procedures on Poultry Inspection Programs advises: Where conventional tank chilling is used, care must be taken to ensure that: sufficient overflow of water is provided to ensure the removal of extraneous matter prior to final icing
.
It is recognized that most poultry plants use a large amount of water during processing and increasing water use can be difficult in some cases.
Order of slaughter
Another practice that can slow pathogen loading in a chill tank is to change the order of slaughter in provincially-licensed abattoirs that slaughter multiple types of poultry on the same processing day, such as broilers, ducks, reds, silkies, pigeons, partridges and fowl.
For Campylobacter risks, once a small number of live birds in a flock become infected with Campylobacter, bird-to-bird transmission within the flock is extremely rapid and many birds in that flock will become infected within a few days. Poultry that are raised together in one barn are considered one flock.
Broilers are likely to be negative for Campylobacter if they are close to or less than 34-36 days of age, while older birds are often positive regardless of breed, such as red birds, pigeon, silkies and other older flocks.
When multiple flocks are slaughtered on the same processing day, good management practices suggest slaughtering the flocks least likely to be positive for Campylobacter first (i.e. younger flocks), followed by other flocks to reduce chill tank contamination and cross-contamination risk.
Chemical intervention
Microbial control interventions are required to be implemented in provincially licensed poultry slaughter plants.
Microbial control interventions in poultry water-based chilling systems are low-cost options for treating chill tanks to prevent carcasses from becoming positive for Campylobacter or Salmonella, and to improve the shelf life of poultry products.
For more information on implementing microbial control interventions, please see Meat Plant Guideline Reference No.: S9.08.13.02 Microbial control interventions for red meat species and poultry.
Contact us
For more information:
- toll Free:
1-877-424-1300 - e-mail: ag.info.omafra@ontario.ca