Degree Type


Date of Award


Degree Name

Master of Science


Animal Science

First Advisor

Joseph G. Sebranek


Increased popularity of natural and organic processed meats can be attributed to the growing consumer demand of preservative-free foods. In order to meet consumer demand, processors have begun using celery juice concentrate in place of sodium nitrite creating no-nitrate-no-nitrite added meat products while maintaining the characteristics unique to conventionally cured processed meats. Natural cures typically have lower ingoing nitrite concentrations which could allow for increased pathogen growth, such as Clostridium perfringens, during cooling as required by USDA, FSIS Appendix B. The objective of this study was to investigate the implications associated with reduced nitrite concentrations and their ability to inhibit C. perfringens outgrowth during a 15 hour cooling cycle. Nitrite treatments of 0 ppm, 50 ppm, and 100 ppm were tested in a broth system inoculated with a three-strain C. perfringens cocktail and treated with a 15 hour stabilization cycle. Samples were collected at 11 pre-determined time/temperature points throughout the cooling cycle in order to evaluate survival of the total C. perfringens population as well as vegetative cells and spores. The lower nitrite concentration of 50 ppm was more effective at preventing C. perfringens outgrowth than 0 ppm, but was not as effective as 100 ppm nitrite. The interaction between nitrite and temperature significantly inhibited (p <0.05) C. perfringens outgrowth in both total population and vegetative cell data. The factors of temperature and nitrite concentration significantly impacted (p <0.05) C. perfringens spores with the interaction between nitrite and temperature having a non-significant (p >0.05) effect on spore outgrowth. Results indicate that decreased nitrite concentrations (50 ppm) have increased potential for total C. perfringens population outgrowth during cooling and may require additional protective measures, such as faster chilling rates.


Copyright Owner

Megan Irene Myers



File Format


File Size

68 pages