Author/Authors :
EL ZAKHEM, H. University of Technology of Compiègne - Centre de Recherche de Royallieu - Department of Chemical Engineering, Lebanon , EL ZAKHEM, H. University of Balamand - Faculty of Engineering, Lebanon , LANOISELLE, J. L. University of Technology of Compiègne - Centre de Recherche de Royallieu - Department of Chemical Engineering, Lebanon , LEBOVKA, N. I. Institute of Biocolloidal Chemistry named after F.D. Ovcharenko, NAS of Ukraine 2, Ukraine , LEBOVKA, N. I. University of Technology of Compiègne - Centre de Recherche de Royallieu - Department of Chemical Engineering, Ukraine , NONUS, M. University of Technology of Compiègne - Centre de Recherche de Royallieu - Department of Chemical Engineering , ALLALI, H. University of Technology of Compiègne - Centre de Recherche de Royallieu - Department of Chemical Engineering , VOROVIEV, E. University of Technology of Compiègne - Centre de Recherche de Royallieu - Department of Chemical Engineering
Abstract :
The aim of this work was to study the efficiency of inactivation of Escherichia coli cells in aqueous suspensions using combined moderate pulsed electric field (PEF) and thermal treatments. The inactivation kinetics of E. coli cells in aqueous suspensions (1 wt%) was monitored using conductometric technique. The electric field strength E was within 5-7.5 kV/cm, the effective PEF treatment time tPEF was within 0- 0.75 s, the pulse duration ti was within 0.3-1 ms, the medium temperature was 30-50°C, and the time of thermal treatment tT was within 0-7000 s. The organic acid concentration was within 0-0.5 g/L.The damage of E. coli was accompanied by release of intracellular components. The synergy between the PEF and thermal treatments in E. coli inactivation was clearly demonstrated. The damage efficiency was noticeably improved by addition of organic acids, especially lactic acid.
Keywords :
Escherichia coli , Pulsed electric fields , Thermal treatment , Electrical conductivity , Organic acids.
