This study measured and compared different temperatures and dwell times of hot water treatment on the reduction of Escherichia coli O157:H7 and Salmonella Typhimurium on beef carcass surfaces. Two different types of beef surfaces, lean and fat, were inoculated with a fecal slurry containing E. coli O157:H7 and S. Typhimurium at ca. 7-log CFU/g, washed to remove gross fecal matter, and rinsed with hot water between 66 and 82 degrees C (150 to 180 degrees F water) for either 5, 10, or 15 s. There were no differences (P > 0.05) in the log reductions of S. Typhimurium and E. coli O157:H7 on the lean surfaces for all three temperature treatments (66, 74, and 82 degrees C). Although the 15 s treatment resulted in a numerically higher log reduction than the other treatments, each of the times resulted in at least a 1 log reduction of both S. Typhimurium and E. coli O157:H7 for lean surfaces. For the fat surfaces, all time treatments for the 82 degrees C and the 10 and 15 s treatments for the 74 degrees C resulted in the highest log reduction for S. Typhimurium. The 5 and 10 s dwell times for treatments at 66 degrees C and the 5 s dwell time at 74 degrees C resulted in the lowest log reduction of S. Typhimurium and E. coli O157:H7. For E. coli O157:H7 all temperature and time treatments resulted in at least a 1 log reduction for the fat surfaces of the outside round. Therefore, hot water treatment is a proven method for reducing both coliforms and pathogenic bacteria.
| Identifer | oai:union.ndltd.org:TEXASAandM/oai:repository.tamu.edu:1969.1/ETD-TAMU-2010-05-7717 |
| Date | 2010 May 1900 |
| Creators | Davidson, Melissa A. |
| Contributors | Harris, Kerri B., Savell, Jeffrey W., Castillo, Alejandro |
| Source Sets | Texas A and M University |
| Language | English |
| Detected Language | English |
| Type | thesis, text |
| Format | application/pdf |
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