Differences in inactivation of Escherichia coli O157:H7 strains in ground beef following repeated high pressure processing treatments and cold storage

作者：Zhou Yijing; Karwe Mukund V; Matthews Karl R^*

来源：Food Microbiology, 2016, 58: 7-12.

DOI：10.1016/j.fm.2016.02.010

• HPP
• Pressure cycling
• Escherichia coli O157:H7
• Ground beef

High pressure processing (HPP) is a safe non-thermal processing method to effectively improve food safety. In this study, HPP treatment followed by cold storage was investigated to reduce Escherichia coli O157:H7 in ground beef. Experiments were conducted using ground beef contaminated with six E. coli O157:H7 strains one at a time or as a cocktail. Control and inoculated ground beef samples were HPP at 25 degrees C, 35 degrees C, and 45 degrees C, at 400 MPa and pre-determined number of pressure cycles totaling a holding time of 15 min. Optimum HPP parameters were 25 degrees C, 400 MPa at five pressure cycles of 3 min each which achieved a 5-log reduction of E. coli O157: H7 in ground beef. Storing HPP processed ground beef at 4 degrees C or -20 degrees C further decreased (P < 0.05) the E. coli O157:H7 population. An effective HPP treatment (5-log reduction) was developed that could be used post-processing to reduce the risk associated with E. coli O157:H7 contamination in ground beef.

• 出版日期2016-9