89D-17 |
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V. C.-H. WU, Dept. of Food Science & Human Nutrition, Univ. of Maine, 5735 Hitchner Hall, Orono, ME 04469-5735 and Y.-H. P. Hsieh, Dept. of Nutrition, Food & Exercise Sciences, Florida State Univ., 436 Sandels Bldg., Tallahassee, FL 32306-1493. Edible Cornus fruit contains tannins and has been used as a tonic in traditional Chinese medicine. Preliminary research conducted by the authors revealed that 3% Cornus fruit extract had significant killing and suppression effects on the foodborne pathogens tested in both water and growth medium. This study evaluated the efficacy of 3% Cornus fruit extract for controlling Escherichia coli O157:H7, Listeria monocytogenes, Salmonella Typhimurium, and Staphylococcus aureus in fresh ground beef. Ground beef samples (20% fat) were thoroughly mixed with Cornus fruit extract to a final concentration of 3% (w/w) in the mixture. The meat blends, along with pure ground beef control samples were then inoculated with each pathogen cocktail (4 log CFU/g) and incubated at either 7o C or 21oC. The 7oC incubation was chosen to simulate a slightly abused refrigerated condition, while the 21oC incubation was designed to observe the growth of these pathogens in ground beef at room temperature. Microbial analysis was performed on each at Days 0, 1, 3, and 5. Results from the 21oC incubation study showed that no significant difference in plate counts was observed between the 3% Cornus fruit-added sample and the control on Day 0. However, there was a significant suppression (2 to 6 log) of all four pathogens on days 1, 3, and 5 compared to the controls. Results from the 7oC incubation study indicated the suppression effect (1 to 3 log) of the extract was visible even from day 0. The addition of Cornus fruit extract is an effective way of suppressing the growth of microorganisms in ground beef at both 7oC and 21oC, and it should be considered for future food product development.
Session 89D, Food Microbiology: Antimicrobial effects on foodborne microorganisms
2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana |