Differences in inactivation of Escherichia coli O157:H7 strains in ground beef following repeated high pressure processing treatments and cold storage. (September 2016)

• Record Type: Journal Article
• Authors: Zhou, Yijing; Karwe, Mukund V.; Matthews, Karl R.
• Is Part Of: Food microbiology. Volume 58(2016:Sep.)
• Page Start: 7
• Page End: 12
• Publication Date: 2016-09
• Subjects: HPP -- Pressure cycling -- Escherichia coli O157:H7 -- Ground beef; Food Microbiology -- Periodicals; Aliments -- Microbiologie -- Périodiques; Food -- Microbiology; Periodicals; Food -- Microbiology -- Periodicals; Food contamination -- Periodicals; 664.001579
• DOI: 10.1016/j.fm.2016.02.010
• Languages: English
• ISSNs: 0740-0020

Abstract

Abstract: 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 °C, 35 °C, and 45 °C, at 400 MPa and pre-determined number of pressure cycles totaling a holding time of 15 min. Optimum HPP parameters were 25 °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 °C or −20 °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. Highlights: Inactivation of Escherichia coli O157:H7 strains are variable at a given HPP treatment. Optimal HHP treatment (five 3 min cycles, 400 MPa, 25 °C) achieved 5 log reduction of E. coli O157:H7. Cold storage for 24 h following HPP treatment serves as additional hurdle for E. coli O157:H7 survival in ground beef.