ARS | Publication request: Inactivation of Listeria monocytogenes on the surface of cooked turkey breast and roast beef using high pressure processing and food grade chemicals

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: January 29, 2007
Publication Date: July 8, 2007
Citation: Jacob, R., Porto Fett, A.C., Luchansky, J.B. 2007. Inactivation of Listeria monocytogenes on the surface of cooked turkey breast and roast beef using high pressure processing and food grade chemicals. Meeting Abstract. IAFP. P2-44.

Technical Abstract: Listeria monocytogenes is frequently associated with outbreaks and recalls of contaminated ready-to-eat red meat and poultry products due to post-processing contamination. Thus, it is necessary to identify treatments that can be applied after processing to reduce the risk of listeriosis. The present study was conducted to evaluate the inactivation of Listeria monocytogenes on the surface of cooked, uncured turkey breast and cooked roast beef by combining high pressure and food grade chemicals. Core samples were aseptically removed from chubs (3 to 5 pounds each) obtained directly from a cooperating manufacturer. The surface of each core sample (4 cm in length and 2 cm in diameter) was uniformly inoculated with a five-strain cocktail (ca. 6.0 to 8.0 log10 CFU/core) of L. monocytogenes and re-packaged in vacuum bags that did or did not contain 2 or 4 ml of antimicrobial. The antimicrobials tested were nisin (Nisaplin at 500 or 1000 ppm) and lauric arginate (LAE at 1 or 10%). The inoculated samples were processed for 5 or 10 min each under 200, 400, or 600 MPa at 20 degree C. In general, the greater the time of treatment, the greater the concentration/volume of antimicrobial, and/or the greater the level of pressure applied, the greater the reduction of L. monocytogenes. Regardless of the treatment, it was possible to decrease pathogen numbers by at least 1.6 log10 CFU/core and by as much as 7.4 log10 CFU/core. The results showed that, when used alone, post-processing treatment with HPP or a food grade chemical reduced pathogen levels by 0.2 to 6.1 log10 CFU/core. HPP in combination with Nisaplin or LAE provided an additional 1.5 log10 CFU/core reduction. Post-processing treatments with Nisaplin or LAE on cooked, uncured turkey and cooked roast beef followed by pressurization can appreciably improve the safety of these products in case of post-processing contamination.