Control of the pathogen Listeria monocytogenes in ready-to-eat (RTE) meats is a major concern in the food industry. The objective of this study was to compare the growth of L. monocytogenes on refrigerated RTE meats containing sodium levulinate (4-oxopentanoic acid, a five carbon organic acid with GRAS status), sodium lactate, or a combination of sodium lactate and sodium diacetate. Turkey roll and bologna were prepared to contain (wt/wt) sodium lactate (2%); sodium lactate in combination with sodium diacetate (1.875% sodium lactate, 0.125% sodium diacetate); sodium levulinate (1, 2, or 3%); or no antilisterial additive. Samples were sliced, inoculated with a 5-strain cocktail (102 to 103 CFU/cm2) of L. monocytogenes, vacuum packaged, and stored at 2°C for 0-12 weeks.
Triplicate packages of each treatment were analyzed bi-weekly for growth of the pathogen. Bacterial counts exceeded 105 CFU/cm2 in controls after 4 weeks in turkey and over 106 CFU/cm2 after 8 weeks in bologna. In turkey, L. monocytogenes showed significant growth in samples containing sodium lactate after 6 weeks(>104 CFU/cm2) and after 8 weeks when used in combination with diacetate. Further, samples containing 1% sodium Jevulinate did not show significant growth of the pathogen for 10 weeks (~104 CFU/cm2), while those containing 2% and 3% levulinate inhibited growth for 12 weeks. In bologna, adding any antimicrobial inhibited growth for 12 weeks.
Finally, Listeria-free samples of turkey roll and bologna, containing the various organic acid salts, were evaluated by members of consumer taste panels. Statistical analysis (ANOV A) showed that there were no differences in overall liking of samples of turkey roll (p = 0.19) or bologna (p = 0.42). In turkey, sodium levulinate was more effective at preventing growth of L. monocytogenes, while in bologna it was as effective as the current industry standards lactate and diacetate. Addition of levulinate did not alter the sensory acceptability of either product
| Identifer | oai:union.ndltd.org:UTAHS/oai:digitalcommons.usu.edu:etd-6604 |
| Date | 01 May 2007 |
| Creators | Thompson, Rebecca L. |
| Publisher | DigitalCommons@USU |
| Source Sets | Utah State University |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | All Graduate Theses and Dissertations |
| Rights | Copyright for this work is held by the author. Transmission or reproduction of materials protected by copyright beyond that allowed by fair use requires the written permission of the copyright owners. Works not in the public domain cannot be commercially exploited without permission of the copyright owner. Responsibility for any use rests exclusively with the user. For more information contact digitalcommons@usu.edu. |
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