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Inactivation of Escherichia coli O157:H7 and Salmonella enteritidis in Liquid Egg White Using Pulsed Electric Field
Author(s) -
Amiali Malek,
Ngadi Michael O.,
Smith James P.,
Raghavan Vijaya G. S.
Publication year - 2006
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/j.1365-2621.2006.tb15637.x
Subject(s) - salmonella enteritidis , escherichia coli , electric field , pathogen , salmonella , enterobacteriaceae , microbiology and biotechnology , inoculation , foodborne pathogen , food science , biology , chemistry , bacteria , biochemistry , physics , listeria monocytogenes , genetics , quantum mechanics , immunology , gene
The effects of temperature and pulsed electric field (PEF) intensity on inactivation of pathogens such as Escherichia coli O157:H7 and Salmonella enteritidis in egg white was investigated. Liquid egg white inoculated with 10 8 colony‐forming units (CFU)/mL of each pathogen was treated with up to 60 pulses (each of 2 JAS width) at electric field intensities of 20 and 30 kV/cm. The processing temperatures were 10°C, 20°C, and 30°C. After treatment, uninjured and total viable cells were enumerated in selective and nonselective agars, respectively. Maximum inactivations of 3.7 and 2.9 log units were obtained for S. enteritidis and E. coli O157:H7, respectively, while injured cells accounted for 0.5 and 0.9 logs for E. coli O157:H7 and S. enteritidis , respectively. For both bacteria, increasing treatment temperature tended to increase the inactivation rate. There was synergy between electric field intensity and processing temperature. The inactivation rate constant k T values for E. coli O157:H7 on both selective and nonselective agars were 8.2 × 10 ‐3 and 6.6 × 10 ‐3 /μS, whereas the values for S. enteritidis were 16.2 × 10 ‐3 and 12.6 × 10 ‐3 /μS, respectively. The results suggest that E. coli O157:H7 was more resistant to heat‐PEF treatment compared with S. enteritidis.