Author
Patel, Jitu | |
Sanglay, Gabriel | |
Sharma, Manan | |
Solomon, Morse |
Submitted to: Journal of Muscle Foods
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 5/9/2006 Publication Date: 1/3/2007 Citation: Patel, J.R., Sanglay, G.C., Sharma, M., Solomon, M.B. 2007. Combining antimicrobials with hydrodynamic pressure processing for control of listeria monocytogenes on frankfurters. Journal of Muscle Foods 18:1-18. Interpretive Summary: Listeria monocytogenes is an important pathogen of concern in ready-to-eat (RTE) meat products. It is ubiquitous in nature, is difficult to completely remove from the processing environment, and is known for its ability to survive in refrigerated environments. Antimicrobials are being used in frankfurters to prevent the outgrowth of L. monocytogenes during refrigerated storage. We evaluated the antilisterial activity of sodium lactate (SL), sodium diacetate (SD), and nisin (N) on frankfurters in combination with hydrodynamic pressure processing (HDP). Frankfurters were surface inoculated with a five-strain mixture of L. monocytogenes after dipping in (1) control (sterile water), (2) 10 percent SL, (3) 5 percent SD, (4) SL + SD, (5) N (5000 IU/ml), (6) N + SL, (7) N + SD, and (8) N + SL + SD for 5 minutes. The frankfurters were vacuum packed and treated with or without hydrodynamic pressure. Frankfurters were periodically analyzed for pH, L. monocytogenes, and aerobic cell populations during storage of 28 days at 4 deg C. HDP treatment significantly reduced L. monocytogenes populations in frankfurters. Dipping treatments containing N showed greater L. monocytogenes reduction compared to that with SL and/or SD treatment, however, the difference was not significant. The combination of nisin and HDP treatment resulted in more than 2 log reduction in L. monocytogenes populations after storage of 28 days. There was a synergistic effect between nisin and HDP for inhibition of L. monocytogenes. These results indicate that the use of nisin as a dipping treatment followed by HDP treatment is more effective than SL or SD for inhibition of the pathogen during storage at 4 deg C. Technical Abstract: The antilisterial activity of sodium lactate (SL), sodium diacetate (SD) and nisin (N) on frankfurters was evaluated in combination with hydrodynamic pressure processing (HDP). Minimum inhibitory concentration (MIC) of these strains as determined in tryptic soy broth was >6 percent, 0.4 percent, and 300 IU/ml for SL, SD, and N, respectively. Frankfurters were surface inoculated with a five-strain mixture of L. monocytogenes after dipping in (1) control (sterile water), (2) 10 percent SL, (3) 5 percent SD, (4) SL + SD, (5) N (5000 IU/ml), (6) N + SL, (7) N + SD, and (8) N + SL + SD for 5 minutes. The frankfurters were vacuum packed and treated with or without hydrodynamic pressure. Frankfurters were periodically analyzed for pH, L. monocytogenes (MOX), and aerobic (TSAYE) cell populations during storage of 28 days at 4 deg C. Antimicrobials and HDP treatment did not change (P<0.05) the frankfurter pH. HDP treatment significantly reduced L. monocytogenes populations in frankfurters. Dipping treatments containing N showed greater L. monocytogenes reduction compared to that with SL and/or SD treatment, however, the difference was not significant. The combination of nisin and HDP treatment resulted in more than 2 log reduction in L. monocytogenes populations after storage of 28 days. There was a synergistic effect between nisin and HDP for inhibition of L. monocytogenes. The reduction pattern in aerobic cell populations during storage of antimicrobials and HDP treated frankfurters was similar to that of L. monocytogenes reduction. These results indicate that the use of nisin as a dipping treatment followed by HDP treatment is more effective for inhibition of the pathogen during storage at 4 deg C. |