ARS | Publication request: The Effects of Polyphosphate Additives on Campylobacter Survival in Processed Chicken Exudates

Submitted to: Applied and Environmental Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 10, 2010
Publication Date: April 1, 2010
Citation: Gunther, N.W. 2010. The Effects of Polyphosphate Additives on Campylobacter Survival in Processed Chicken Exudates. Applied and Environmental Microbiology. 76(8):2419-2424.

Interpretive Summary: Campylobacter species are the bacteria responsible for the largest percentage of food poisoning cases occurring each year in the developed world. Consumption of improperly cooked poultry or cross contamination of other foodstuffs by uncooked poultry is the primary cause of Campylobacter infections in humans. Polyphosphates are materials generally considered safe as food additives, which the poultry industry utilize in marinades added to a significant portion of the poultry processed each year for consumer sale. When the survival of Campylobacter in the liquid drippings of poultry treated with polyphosphate-containing marinades was compared to the drippings of poultry not treated with any phosphates, significantly enhanced survival of the Campylobacter in the poultry drippings containing polyphosphates was observed. Additionally, this enhanced survival caused by the presence of polyphosphates was observed to occur under the refrigeration conditions that consumers would normally store poultry before preparation. This research suggests that polyphosphate usage in poultry can lead to an increased number of Campylobacter bacteria being present in poultry products sold to consumers. The increased number of Campylobacter would therefore increase the opportunity for Campylobacter species to cause human disease through improper preparation of poultry or cross-contamination. Therefore, polyphosphates usage in poultry processing present a potential food safety risk.

Technical Abstract: Campylobacter spp. are responsible for a large number of food-borne illness cases worldwide. Despite being sensitive to oxygen and nutritionally fastidious, Campylobacter spp. are able to survive in food processing environments and reach consumers in sufficient numbers to cause disease. To investigate Campylobacter’s persistence on processed chicken, exudates from chickens produced for consumer sale were collected and sterilized. Two types of exudates were collected, from enhanced or non-enhanced chicken products. Exudates from enhanced chicken products examined in this study contained a mixture of polyphosphates. Exudate samples were inoculated with C. jejuni or C. coli strains, incubated under a range of environmental conditions, and viable bacteria present in the resultant cultures were enumerated. When incubated at 42C in a microaerobic environment, exudates from enhanced chicken products resulted in increased survival of C. jejuni and C. coli versus non-enhanced exudates in the range of 1 to 6 log CFU/ml. Under more relevant food storage conditions (4C and normal atmosphere), the exudates from enhanced chicken also demonstrated improved Campylobacter survival compared with non-enhanced exudates. Polyphosphates present in the enhanced exudates were determined to be largely responsible for the improved survival observed when comparing the two types of exudates. Therefore, polyphosphates used to enhance chicken aid in sustaining the numbers of Campylobacter, increasing the opportunity for disease via cross contamination or improperly cooked chicken.