Inactivation of Escherichia Coli 0157:H7 and Salmonella Enteritidis in Liquid Egg Using Continuous Pulsed Electric Field System

2006 ◽  
Vol 1 (5) ◽  
Author(s):  
Malek Amiali ◽  
Michael Ngadi ◽  
James P. Smith ◽  
Vijaya Raghavan
Keyword(s):  
Escherichia Coli ◽  
Electric Field ◽  
Field Intensity ◽  
Electric Field Intensity ◽  
Salmonella Enteritidis ◽  
Processing Temperature ◽  
Bacterial Inactivation ◽  
E Coli ◽  
Liquid Whole Egg ◽  
Whole Egg

This study sought to evaluate the effect of PEF parameters such as electric field intensity and number of pulses on the inactivation of Escherichia coli O157:H7 and Salmonella Enteritidis suspended in liquid whole egg. The medium was inoculated with 108 CFU ml-1 of E. coli O157:H7 or S. Enteritidis and was treated continuously at 10, 20 or 30°C using electric field intensity of either 20 or 30 kV cm-1. A biphasic instant reversal PEF waveform with up to 105 pulses of 2 µs in width was applied. Bacterial inactivation increased with increasing applied electric field intensity, number of pulses and processing temperature. Maximum reductions of 3.9 and 3.6 log cycles were obtained for E. coli O157:H7 and S. Enteritidis, respectively. The maximum input energies required to inactivate E. coli O157:H7 and S. Enteritidis were 538 and 914 J, respectively. The higher kinetic value was obtained for S. Enteritidis (0.043 µs-1) representing the more heat–PEF sensitive bacteria compared to E. coli O157:H7.

scholarly journals Synergistic Effect of Pulsed Electric Fields and Temperature on The Inactivation of Microorganismsill

2021 ◽  
Author(s):  
Zeyao Yan ◽  
Li Yin ◽  
Chunjing Hao ◽  
Kefu Liu ◽  
Jian Qiu
Keyword(s):  
Escherichia Coli ◽  
Saccharomyces Cerevisiae ◽  
Electric Field ◽  
Electric Fields ◽  
Field Intensity ◽  
Electric Field Intensity ◽  
Pulsed Electric Fields ◽  
Nucleic Acid Content ◽  
Bacillus Velezensis ◽  
Inactivation Effect

Abstract Pulsed electric fields (PEF) as a new pasteurization technology played an important role in the process of inactivating microorganisms. At the same time, temperature could promote the process of electroporation, and achieve better inactivation effect. This article studied the inactivation effect of PEF on Saccharomyces cerevisiae, Escherichia coli, and Bacillus velezensis under different initial temperatures (room temperature-24°C, 30°C, 40°C, 50°C). From the inactivation results, it found temperature could reduce the critical electric field intensity for microbial inactivation. After the irreversible electroporation of microorganisms occurred, the nucleic acid content and protein content in the suspension increased with the inactivation rate because the cell membrane integrity was destroyed. We had proved that the electric field and temperature could promote molecular transport through the finite element simulation. Under the same initial temperature and electrical parameters (electric field intensity, pulse width, pulse number), the lethal effect on different microorganisms was Saccharomyces cerevisiae > Escherichia coli > Bacillus velezensis.

Synergystic Effect of Temperature and Electric Field Intensity in Escherichia coli Inactivation

2014 ◽  
Vol 6 (2) ◽  
pp. 79-86
Author(s):  
A.M. Oliva ◽  
A. Homs-Corbera ◽  
E. Torrents ◽  
A. Juarez ◽  
J. Samitier
Keyword(s):  
Escherichia Coli ◽  
Electric Field ◽  
Field Intensity ◽  
Electric Field Intensity ◽  
Effect Of Temperature

Membrane Damage and Viability Loss of Escherichia coli K-12 and Salmonella Enteritidis in Liquid Egg by Thermal Death Time Disk Treatment†

2008 ◽  
Vol 71 (10) ◽  
pp. 1988-1995 ◽  
Author(s):  
DIKE O. UKUKU ◽  
TONY JIN ◽  
HOWARD ZHANG
Keyword(s):  
Salmonella Enteritidis ◽  
Membrane Damage ◽  
E Coli ◽  
Viability Loss ◽  
Death Time ◽  
Thermal Death ◽  
Liquid Whole Egg ◽  
K 12 ◽  
Thermal Death Time ◽  
Whole Egg

Bacterial injury, including leakage of intracellular substance and viability loss, of Escherichia coli K-12 (ATCC 23716) and Salmonella Enteritidis (ATCC 13076) inoculated in liquid egg white and liquid whole egg was determined by thermal death time disk. E. coli K-12 and Salmonella Enteritidis were inoculated in liquid egg white and liquid whole egg to a final count of 7.8 log CFU/ml and were thermally treated with thermal death time disks at room temperature (23°C), 54, 56, 58, and 60°C from 0 to 240 s. Sublethal injury, leakage of intracellular substances, and viability loss of E. coli K-12 and Salmonella Enteritidis was investigated by plating 0.1 ml on selective trypticase soy agar containing 3% NaCl, 5% NaCl, sorbitol MacConky agar, and xylose lysine sodium tetradecylsulfate and nonselective trypticase soy agar. No significant (P >0.05) differences on percent injury or viability loss for E. coli K-12 and Salmonella populations were determined in all samples treated at 23°C. Sublethal injury occurred in E. coli and Salmonella populations at 54°C or above for 120 s. Viability losses for both bacteria averaged 5 log at 54°C or above for 180 s, and the surviving populations were below detection (<10 CFU/ml). Thermal treatment at 40°C and above led to membrane damage, leakage, and accumulation of intracellular ATP from 2 to 2.5 log fg/ml and UV-absorbing substances of 0.1 to 0.39 in the treated samples. These results indicate similar thermal injury/damage on both E. coli and Salmonella membranes as determined by the amount of inactivation, viability loss, and leakage of intracellular substances of bacteria.

PULSED ELECTRIC FIELD TREATMENT OF LIQUID WHOLE EGG INOCULATED WITH SALMONELLA ENTERITIDIS

2004 ◽  
Vol 24 (1) ◽  
pp. 71-85 ◽  
Author(s):  
N. HERMAWAN ◽  
G. AKDEMIR EVRENDILEK ◽  
W.R. DANTZER ◽  
Q.H. ZHANG ◽  
E.R. RICHTER
Keyword(s):  
Electric Field ◽  
Salmonella Enteritidis ◽  
Pulsed Electric Field ◽  
Liquid Whole Egg ◽  
Whole Egg ◽  
Pulsed Electric Field Treatment ◽  
Electric Field Treatment

scholarly journals Synergistic effect of pulsed electric fields and temperature on the inactivation of microorganisms

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zeyao Yan ◽  
Li Yin ◽  
Chunjing Hao ◽  
Kefu Liu ◽  
Jian Qiu
Keyword(s):  
Escherichia Coli ◽  
Saccharomyces Cerevisiae ◽  
Electric Field ◽  
Electric Fields ◽  
Field Intensity ◽  
Electric Field Intensity ◽  
Pulsed Electric Fields ◽  
Nucleic Acid Content ◽  
Bacillus Velezensis ◽  
Inactivation Effect

AbstractPulsed electric fields (PEF) as a new pasteurization technology played an important role in the process of inactivating microorganisms. At the same time, temperature could promote the process of electroporation, and achieve better inactivation effect. This article studied the inactivation effect of PEF on Saccharomyces cerevisiae, Escherichia coli, and Bacillus velezensis under different initial temperatures (room temperature-24 $$\mathrm{^\circ{\rm C} }$$ ∘ C , 30 $$\mathrm{^\circ{\rm C} }$$ ∘ C , 40 $$\mathrm{^\circ{\rm C} }$$ ∘ C , 50 $$\mathrm{^\circ{\rm C} }$$ ∘ C ). From the inactivation results, it found temperature could reduce the critical electric field intensity for microbial inactivation. After the irreversible electroporation of microorganisms occurred, the nucleic acid content and protein content in the suspension increased with the inactivation rate because the cell membrane integrity was destroyed. We had proved that the electric field and temperature could promote molecular transport through the finite element simulation. Under the same initial temperature and electrical parameters (electric field intensity, pulse width, pulse number), the lethal effect on different microorganisms was Saccharomyces cerevisiae > Escherichia coli > Bacillus velezensis.

High-speed isotachophoresis. Analytical aspects of the steady-state longitudinal temperature profiles

1979 ◽  
Vol 44 (3) ◽  
pp. 841-853 ◽  
Author(s):  
Zbyněk Ryšlavý ◽  
Petr Boček ◽  
Miroslav Deml ◽  
Jaroslav Janák
Keyword(s):  
Steady State ◽  
Temperature Distribution ◽  
Electric Field ◽  
Field Intensity ◽  
Electric Field Intensity ◽  
Minor Component ◽  
Physical Models ◽  
Temperature Profiles ◽  
Longitudinal Temperature ◽  
Continuous Character

The problem of the longitudinal temperature distribution was solved and the bearing of the temperature profiles on the qualitative characteristics of the zones and on the interpretation of the record of the separation obtained from a universal detector was considered. Two approximative physical models were applied to the solution: in the first model, the temperature dependences of the mobilities are taken into account, the continuous character of the electric field intensity at the boundary being neglected; in the other model, the continuous character of the electric field intensity is allowed for. From a comparison of the two models it follows that in practice, the variations of the mobilities with the temperature are the principal factor affecting the shape of the temperature profiles, the assumption of a discontinuous jump of the electric field intensity at the boundary being a good approximation to the reality. It was deduced theoretically and verified experimentally that the longitudinal profiles can appreciably affect the longitudinal variation of the effective mobilities in the zone, with an infavourable influence upon the qualitative interpretation of the record. Pronounced effects can appear during the analyses of the minor components, where in the corresponding short zone a temperature distribution occurs due to the influence of the temperatures of the neighbouring zones such that the temperature in the zone of interest in fact does not attain a constant value in axial direction. The minor component does not possess the steady-state mobility throughout the zone, which makes the identification of the zone rather difficult.

POLARON IN A QUANTUM DOT UNDER AN ELECTRIC FIELD

2007 ◽  
Vol 21 (24) ◽  
pp. 1635-1642
Author(s):  
MIAN LIU ◽  
WENDONG MA ◽  
ZIJUN LI
Keyword(s):  
Quantum Dot ◽  
Electric Field ◽  
Field Intensity ◽  
Ground State Energy ◽  
Ground State ◽  
Electric Field Intensity ◽  
State Energy ◽  
Theoretical Study ◽  
The Moment ◽  
Transformation Methods

We conducted a theoretical study on the properties of a polaron with electron-LO phonon strong-coupling in a cylindrical quantum dot under an electric field using linear combination operator and unitary transformation methods. The changing relations between the ground state energy of the polaron in the quantum dot and the electric field intensity, restricted intensity, and cylindrical height were derived. The numerical results show that the polar of the quantum dot is enlarged with increasing restricted intensity and decreasing cylindrical height, and with cylindrical height at 0 ~ 5 nm , the polar of the quantum dot is strongest. The ground state energy decreases with increasing electric field intensity, and at the moment of just adding electric field, quantum polarization is strongest.

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