Date of Award


Document Type


Degree Name

Master of Science (MS)

Legacy Department

Food, Nutrition, and Culinary Science


Dawson, Paul L


ABSTRACT The presence of thermo-resistant bacteria in products from the rendering industry is a concern in the United States because only about 80% of the rendering industries use thermal processing to eliminate bacteria. The objective of this study was to determine the thermal inactivation characteristics of thermo-resistant bacteria from raw rendering materials. Ground beef with 21% protein, 19% fat, and 60% moisture was used as a model media to simulate raw rendering material. Raw animal co-products were heated at 91, 95, 96¡C for 90 min, then surviving bacteria were recovered. These heat resistant isolates were inoculated into meat samples then thermally treated using a dry bath incubator. Calculations for D and Z values were determined for thermo-resistant bacteria subjected to thermal treatment at 90.88¡C, 94.84¡C, and 95.90¡C. This study demonstrated that thermally resistant bacteria isolated from raw rendering materials exhibit high heat resistance for a wide range of temperature, suggesting that use of thermal processing at an optimized temperate (> 96¡C) is required for an efficient removal of microbes.

Included in

Microbiology Commons