My watch list  

Effect of Continuous Ohmic Heating to inactivate Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes in Orange and Tomato Juice


Aims:  The purpose of this study is to investigate the efficacy of continuous ohmic heating for reducing Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes in orange and tomato juice.

Methods and Results:  Orange and tomato juice were treated with electric field strengths in the range of 25–40 V/cm for different treatment times. The temperature of the samples increased with increasing treatment time and electric field strength. The rate of temperature change for tomato juice was higher than for orange juice at all voltage gradients applied. Higher electric field strength or longer treatment time resulted in a greater reduction of pathogens. E. coli O157:H7 was reduced by more than 5 log after 60, 90, and 180 s treatment in orange juice with 40, 35, and 30 V/cm electric field strength, respectively. In tomato juice, treatment with 25 V/cm for 30 s was sufficient to achieve a 5 log reduction of E. coli O157:H7. Similar results were observed in S. Typhimurium and L. monocytogenes. The concentration of vitamin C in continuous ohmic heated juice was significantly higher than in conventionally heated juice (P < 0·05).

Conclusions:  Continuous ohmic heating can be effective at killing foodborne pathogens on orange and tomato juice with lower degradation of quality than conventional heating.

Significance and Impact of Study:  These results suggest that continuous ohmic heating might be effectively used to pasteurize fruit and vegetable juice in a short operating time and that the effect of inactivation depends on applied electric field strengths, treatment time and electric conductivity.

© 2012The Authors Journal of Applied Microbiology © 2012 The Society for Applied Microbiology

Authors:   Lee, Su‐Yeon; Sagong, Hun‐Gu; Ryu, Sangryeol; Kang, Dong‐Hyun
Journal:   Journal of Applied Microbiology
Year:   2012
Pages:   no
DOI:   10.1111/j.1365-2672.2012.05247.x
Publication date:   31-Jan-2012
Facts, background information, dossiers
  • heating
  • temperature
  • reductions
  • concentration
More about Wiley
Your browser is not current. Microsoft Internet Explorer 6.0 does not support some functions on Chemie.DE