Submitted to: Journal of Food Protection
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/8/2005
Publication Date: 7/1/2005
Citation: Hinton Jr, A., Ingram, K.D. 2005. Microbicidal activity of tripotassium phosphate and fatty acids towards pathogenic and spoilage bacteria associaed with processed poultry. Journal of Food Protection. 68:1462-1466. Interpretive Summary: Most poultry processors currently use chlorine as a disinfectant to reduce microbial contamination in poultry processing operations. Nonetheless, contaminated poultry continues to be a major source of human foodborne diseases. The purpose of these experiments was to examine the ability of solutions of tripotassium phosphate (TPP) and mixtures of TPP and two fatty acids (lauric and myristic acid) to kill microorganisms associated with processed poultry. In the first set of experiments, bacteria and yeasts isolated from processed chickens were added to solutions of TPP and to mixtures of TPP with lauric or myristic acid. After mixing for 5 minutes, the number of bacteria that were still alive in the liquids was determined. Results indicated that TPP solutions and mixtures of TPP solutions and fatty acids can kill bacteria and yeasts associated with processed poultry. In the next set of experiments, the ability of these solutions to kill bacteria on chicken skin was determined. The chicken skin samples were washed in mixtures of TPP and fatty acids, and the number of microorganisms remaining on the skin was determined. Results indicated that washing the skin in TPP-fatty acid mixtures reduced the number of some types bacteria on the skin, but other bacteria were able to survive the treatment. Apparently, fats and proteins from the chicken skin limited the ability of TPP-fatty acid mixtures to kill some of these microorganisms. Findings from these experiments indicate that under some conditions, mixtures of TPP and fatty acids can kill microorganisms associated with poultry. Further research will be conducted to compare the antimicrobial activity of mixtures of TPP and fatty acids with other chemicals used to kill microorganisms associated with poultry processing.
Technical Abstract: The ability of solutions of tripotassium phosphate (TPP) and fatty acids (lauric and myristic acid) to reduce populations of spoilage and pathogenic microorganisms associated with processed poultry was examined. In vitro studies were conducted using cultures of bacteria (Campylobacter jejuni, Escherichia coli, Listeria monocytogenes, Pseudomonas aeruginosa, Salmonella Typhimurium, and Staphylococcus aureus) and yeasts (Candida ernobii and Yarrowia lipolytica). Cultures of the bacteria and yeasts were suspended in solutions of TPP or mixtures of TPP with lauric or myristic acid for 5 min, and viable colony-forming-units (cfu)/ml in the suspensions were enumerated on microbiological agar. Results indicated that TPP solutions are highly bactericidal towards Gram-negative bacteria and that mixtures of TPP solutions and fatty acids are highly microbicidal against Gram-negative bacteria, Gram-positive bacteria, and yeasts. The microbicidal activity of mixtures of TPP and fatty acids towards the native bacteria flora of skin of processed broiler carcasses was also examined. Skin samples were washed in TPP/fatty acid mixtures; and the population of total aerobic bacteria, campylobacter, enterococci, Escherichia coli, lactic acid bacteria, pseudomonads, staphylococci, and yeasts in the skin rinsates was enumerated on the appropriate microbiological media. Results indicated that washing the skin in mixtures of TPP and fatty acids produced significant reductions in the number of aerobic bacteria, campylobacter, E. coli, pseudomonads, and yeasts recovered from skin rinsates, but no significant reductions in the populations of enterococci, lactic acid bacteria, or staphylococci. These findings indicate that mixtures of TPP and fatty acids possess microbicidal activity against several microorganisms associated with processed poultry and that these solutions may be useful as microbicides to reduce the populations of some bacteria and yeasts associated with poultry processing.