Submitted to: Meeting Abstract
Publication Type: Proceedings
Publication Acceptance Date: 9/20/2005
Publication Date: 10/23/2005
Citation: Bari, M.L., Mori, M., Ukuku, D.O., Kawamoto, S., Kawamoto, K. 2005. Efficiency of high pressure treatment on the inactivation of escherichia coli 0157:h7 in tomato juice and liquid whole egg. In: Proceedings of the United States-Japan Cooperative program in Natural Resources (UJNR) Food and Agriculture Panel, 34st Annual meeting, October 23-29, 2005. Susono, Shizuoka, Japan. P. 349-355.
Technical Abstract: Liquid foods have been implicated in numerous food-borne outbreaks and recalls. A non-thermal high-pressure treatment at 25oC was used to preserve and reduce E. coli 0157:H7 population of tomato Juice and liquid whole egg. Tomato Juice and liquid whole egg were individually inoculated with E. coli 0157:H7 at 108 cfu/ml and then exposed to continuous or repeated cycles of high-pressure treatment at 25oC. Treatments using moderate pressure at 300MPa, 350MPa and 400 MPa for up to 60 min reduced the population of inoculated E. coli O157:H7 by approximately 3.0, 3.0 and 5.0 log cycles, respectively in tomato juice. A 4.0 log reduction of E. coli O157:H7 was achieved in whole liquid egg at 400 MPa at 40 min. Population of E. coli O157:H7 in all samples tested was decreased when temperature was increased from 30-50oC. However, increase in temperature with a 600MPa pressure resulted to coagulation of the liquid eggs, and more injured cells were recovered in tomato juice than liquid egg. Repeating the pressure 4 times at 300 MPa for a total of 40 min at room temperature was significant (p<0.05) in reducing E. coli population by extra 1 log. The results of this study suggests that repeating high-pressure treatment at least 4 times at 300 MPa for a total of 40 min would inactivate more E. coli O157:H7 strains in liquid whole egg and tomato juice than using continuous pressure for the same amount of time.