Submitted to: Meeting Abstract
Publication Type: Abstract only
Publication Acceptance Date: 7/31/2003
Publication Date: 8/10/2003
Citation: Call, J.E., Nicholson, M.D., Luchansky, J.B. 2003. Evaluation of nisin-coated cellulose casings for control of listeria monocytogenes on the surface of frankfurters formulated with lactates and stored at 4 deg c. International Association for Food Protection. Abstract #P069, p. 83. Interpretive Summary:
Technical Abstract: In the last four years, Listeria monocytogenes (Lm) has been associated with two large outbreaks of listeriosis involving frankfurters and has been responsible for a number of large and small recalls of RTE meats. Biopreservatives such as nisin and various salts of organic acids such as potassium lactate and sodium diacetate have also proven effective in the control of Lm in various foods including RTE meats. The present study was conducted to determine if commercially-produced frankfurters made with pork, beef, and turkey and formulated with 1.32% potassium lactate and 0.09% sodium diacetate that were subsequently processed in cellulose casings coated with and without nisin (ca. 50,000 I.U. per square inch of surface area) would control the outgrowth of Lm during extended refrigerated storage. Packages containing the peeled frankfurters (4 links per package) were inoculated with approximately 5 log10 CFU per package of a five-strain mixture of Lm, vacuum-packaged, and stored at 4°C for 45 days. Survivors were recovered and enumerated by rinsing each package with 18 ml of sterile 0.1% peptone water and direct plating with and without prior dilution in 0.1% peptone water onto MOX selective agar. The data for each of two trials were averaged. In packages containing frankfurters prepared in nisin-coated casings, the Lm levels decreased by about 1.1 log10 CFU per package after 45 days of storage at 4°C. In comparison, Lm levels decreased by about 0.4 log10 CFU per package in frankfurters prepared in casings that were not coated with nisin. In a related study, using the same nisin-coated casings and frankfurter formulation, similar results were obtained using a different three-strain mixture of Lm strains, demonstrating that these antimicrobials are effective against a variety of strains. These data establish that potassium lactate and sodium diacetate used alone and in combination with nisin-coated casings can enhance the safety of frankfurters by controlling the levels of Lm during storage at 4°C.