Document Detail


Generation of bactericidal and mutagenic components by pulsed electric field treatment.
MedLine Citation:
PMID:  15135955     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Inactivation of stationary phase Escherichia coli, Salmonella Typhimurium and Listeria innocua (10(8) CFU/ml) by high intensity pulsed electric fields (PEF) was studied in water and different buffers at pH 7.0. The fraction of survivors after PEF treatment with 300 pulses (5 Hz) of 26.7 kV/cm and a pulse width of 2 micros varied between 0.050% and 55%, but was always lower in Tris-HCl buffer than in HEPES-KOH buffer and water. When cell suspensions were stored for 24 h at 25 degrees C after PEF treatment, the survivor fraction further decreased, except for E. coli in water and HEPES-KOH. By following the survival of untreated cells added to water or buffers that were previously PEF treated, this secondary inactivation could be ascribed to the formation of bactericidal components as a result of PEF treatment. Buffers and water containing 10 mM NaCl became bactericidal against all three bacteria upon PEF treatment, and the bactericidal effect could be neutralized by thiosulfate, suggesting that chlorine and/or hypochlorite had been formed. Also in the absence of Cl- ions, PEF treated water and buffers had bactericidal properties, but the specificity of the bactericidal effects against different bacteria differed depending on the buffer used. In the Ames mutagenicity test using His- S. Typhimurium mutant strains, PEF treated Tris buffers containing 10 mM Cl- ions, as well as PEF treated grape juice showed a mutagenic effect. The implications of these findings for the safety of PEF treated foods are discussed.
Authors:
Kristien M F A Reyns; Ann M J Diels; Chris W Michiels
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  International journal of food microbiology     Volume:  93     ISSN:  0168-1605     ISO Abbreviation:  Int. J. Food Microbiol.     Publication Date:  2004 Jun 
Date Detail:
Created Date:  2004-05-11     Completed Date:  2004-08-26     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8412849     Medline TA:  Int J Food Microbiol     Country:  Netherlands    
Other Details:
Languages:  eng     Pagination:  165-73     Citation Subset:  IM    
Copyright Information:
Copyright 2003 Elsevier B.V.
Affiliation:
Katholieke Universiteit Leuven, Department of Food and Microbial Technology, Laboratory of Food Microbiology, Kasteelpark Arenberg 22, B-3001 Leuven, Belgium.
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MeSH Terms
Descriptor/Qualifier:
Colony Count, Microbial
Electric Conductivity
Electric Stimulation*
Escherichia coli / growth & development*
Food Microbiology
Food Preservation / methods*
Hydrogen-Ion Concentration
Listeria / growth & development*
Salmonella typhimurium / growth & development*
Sodium Chloride / pharmacology
Chemical
Reg. No./Substance:
7647-14-5/Sodium Chloride

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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