Effects of pH, temperature, and pre-pulsed electric field treatment on pulsed electric field and heat inactivation of Escherichia coli O157:H7.
This investigation was undertaken to study the inactivation of Escherichia coli O157:H7 by pulsed electric field (PEF) treatment and heat treatment after exposure to different stresses. E. coli O157:H7 cells exposed to different pHs (3.6, 5.2, and 7.0 for 6 h). different temperatures (4, 35, and 40 degrees C for 6 h), and different pre-PEF treatments (10, 15, and 20 kV/cm) were treated with PEFs (20, 25, and 30 kV/cm) or heat (60 degrees C for 3 min). The results of these experiments demonstrated that a pH of 3.6 and temperatures of 4 and 40 degrees C caused significant decreases in the inactivation of E. coli O157:H7 by PEF treatment and heat treatment (P < 0.05). Pre-PEF treatments, pHs of 5.2 and 7.0, and a temperature of 35 degrees C, on the other hand, did not result in any resistance of E. coli O157:H7 cells to inactivation by PEF treatment and heat treatment (P > 0.05).
Faculty of Agriculture, Department of Food Engineering, Mustafa Kemal University, Tayfur Sokmen Campus, 31040 Alahan, Hatay, Turkey. gevrendilek@mku.edu.tr
Gulsun Akdemir
GA
Evrendilek
Q Howard
QH
Zhang
D015169:Colony Count, Microbial; D004560:Electricity; D019453:Escherichia coli O157 / Q000254:growth & development*; D005516:Food Microbiology; D005519:Food Preservation / Q000379:methods; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D013997:Time Factors