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

Osvaldo López-Cuevas Et Al

doi:10.15414/jmbfs.2017.7.2.149-152

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.

Highlights

The increasing worldwide tendency of including fresh produce on the diet has been related to the occurrence of foodborne illnesses due to consumption of contaminated produce
We hypothesized that aqueous chlorine dioxide applied by spraying on green bell peppers has a better effect on microbial reduction than sodium hypochlorite
The use of sodium hypochlorite and chlorine dioxide for reduction of E. coli O157:H7 from bell pepper surface, showed different and significant results according to disinfectant product (p=0.000), pH (p=0.013) and time of contact (p=0.000), the interaction pH-disinfectant showed significant differences, indicating that lowering pH values can negatively affect the bactericidal effect of both disinfectants [Table 2]

Summary

Introduction

The increasing worldwide tendency of including fresh produce on the diet has been related to the occurrence of foodborne illnesses due to consumption of contaminated produce. Microbial contamination throughout the production chain may occur as a consequence of inadequate or scarce sanitation process during production chain, resulting in diverse punctual contamination sources, especially when Good Agricultural and Manufacturing Practices are not strictly followed (Cummings et al, 2001; CDC, 2002; CDC, 2003; CDC, 2005; CDC, 2008) Pathogenic bacteria, such as Escherichia coli O157:H7 has been responsible for at least 18 foodborne outbreaks in the last ten years in the United States, and nine of these were related to vegetables (CDC, 2016) causing economic losses up to $271 million dollars per year (Hoffmann et al, 2015). In another study by Pao et al (2007) evaluated chlorine dioxide at 20 mg L-1 on tomatoes surface by the immersion method, reaching reductions up to 5 Log CFU/cm of Salmonella enterica and Erwinia carotovora. The objective of this research was to compare the spraying application of chlorine dioxide and sodium hypochlorite in reducing E. coli O157:H7 inoculated on bell pepper surface simulating packinghouses disinfection operation

Objectives

Methods

Results