In response to two large ground turkey recalls in recent years prompted by human illness outbreaks tied to two serotypes of Salmonella, the United States Department of Agriculture Food Safety and Inspection Service announced changes to its ground poultry Salmonella sampling program. The sample size for ground poultry was increased from 25 grams to 325 grams, which makes it much more likely that Salmonella will be found in an individual sample. The Food Safety and Inspection Service will also include mechanically separated poultry into the ground poultry Salmonella sampling program for the first time.
Dr. Shelley McKee, associate professor, Auburn University, said that samples of mechanically separated chicken and mechanically separated turkey can be positive for Salmonella 70 percent to 90 percent of the time with 25-gram samples. Mechanically separated product produced by a plant may be excluded from the Salmonella sampling program if the plant can demonstrate that this product is only used by federally inspected facilities to produce ready-to-eat products.
McKee said that Salmonella tests performed by the USDA utilize an enrichment method that makes it possible to detect Salmonella in ground poultry products even if it is present at very low levels. McKee, who spoke at the Turkey Processor Workshop at the Midwest Poultry Federation Convention, said that the increased sample size will make it difficult for poultry processors to meet Salmonella performance standards for ground products without taking additional steps to try and reduce the load on parts prior to the grinder.
Two suggestions to reduce Salmonella load
Based on her work with poultry processors and in the laboratory, McKee had two suggestions for poultry processors looking to reduce the Salmonella load on parts. Almost all U.S. poultry processors utilize immersion chilling systems to both chill the birds and apply antimicrobial agents, which result in post-chill Salmonella test results that are significantly lower than corresponding pre-chill tests. She said that many poultry processors do not employ the antimicrobial agents in the pre-chiller. McKee expressed concern that moisture picked up in the pre-chiller may be bringing a bacterial load along with it and that this bacteria is not all killed in subsequent chillers. She suggested that processors should look at what is going on in their pre-chiller and adjusting how it is being used to make sure that moisture picked up during chilling doesn’t wind up increasing bacterial loads when the carcasses are cut-up. “You need to treat birds before the pre-chiller or put your antimicrobials in the pre-chiller,” she said.
The use of post chill antimicrobial sprays and dips show promise for reducing Salmonella on parts prior to grinding, according to McKee. She said that in a test situation, you are looking for a treatment that will give a two log reduction. She said that the sprays will only give about a half log reduction, so you would need to have multiple sprays to get the result you need. Total immersion dips with a dwell time as short as 20 seconds were found to be more effective than sprays or rinses and do not have any negative organoleptic impact on the products.
Whether used as a spray or a dip, the two antimicrobials tested that worked most efficiently and effectively were peracetic acid at 700 parts per million and cetylpyridinium chloride at a 0.6 percent solution. “The two that I would go to any time are [cetylpyridinium chloride] and [peracetic acid], and they both can be very effective,” McKee said. In these short contact time “parts decontamination units” you have a very high concentration of antimicrobial. McKee said that chlorine is not effective in this type of application because of the short contact time.
Tips on reassessments
When discussing the mandatory reassessments of HACCP programs for poultry processors who make ground products, McKee said, “It isn’t just how much Salmonella you have but what serotypes you have. Are your serotypes of human health concern?”
She said that if you find a serotype at the plant of human health concern in your reassessment, expect that you will be asked by Food Safety and Inspection Service about the control measures you are taking on the farm for that serotype.
McKee said that the two Salmonella serotypes involved in the two large ground turkey recalls, Salmonella Heidelberg and Salmonella Hadar, are both common and persistent in turkeys. She also said that Salmonella enteritidis, which used to be rare in turkeys and broilers, is now very prevalent in the broiler industry.