INACTIVATION OF ESCHERICHIA COLI O157:H7 ON GREEN BELL PEPPER BY CHLORINE DIOXIDE SIMULATING PACKINGHOUSES PROCESS

Abstract

In this study, packinghouses spraying disinfection process was simulated to compare the effectiveness of aqueous chlorine dioxide and sodium hypochlorite in reducing Escherichia coli O157:H7 on bell pepper surface. Bell peppers inoculated with 7.74 Log10 CFU of E. coli O157:H7 were placed in a rotary mixer (60 rpm), and sprayed with chlorine dioxide and sodium hypochlorite. Chlorine dioxide at 5 mg L-1 during 20-30 s reduces from 7.74 Log10 CFU of E. coli O157:H7 adhered on bell pepper to undetectable numbers, while the exposition with chlorine dioxide at pH 6 and 8 during 10 s was necessary to reduce 4.25 and 3.90 Log10 CFU, respectively. On the other hand, sodium hypochlorite at 200 mg L-1 at pH 6 reduced 2.89, 3.25 and 3.54 Log10 CFU/bell pepper at 10, 20 and 30 s, respectively. Spraying disinfection process using aqueous chlorine dioxide was more effective than sodium hypochlorite applications, therefor chlorine dioxide is an effective alternative to reduce E. coli O157:H7 on bell pepper surface.