Efficacy of antimicrobials for the disinfection of pathogen contaminated green bell pepper and of consumer cleaning methods for the decontamination of knives.

Research paper by Keila L KL Perez, Lisa M LM Lucia, Luis L Cisneros-Zevallos, Alejandro A Castillo, T Matthew TM Taylor

Indexed on: 06 Apr '12Published on: 06 Apr '12Published in: International Journal of Food Microbiology


While there is strong focus on eliminating pathogens from produce at a commercial level, consumers can employ simple methods to achieve additional pathogen reductions in the domestic kitchen. To determine the ability of antimicrobials to decontaminate peppers, samples of green bell pepper were inoculated with Salmonella enterica and Escherichia coli O157:H7 and then immersed in 3% (v/v) hydrogen peroxide (H₂O₂), 2.5% (v/v) acetic acid (AA), 70% (v/v) ethyl alcohol (EtOH), or sterile distilled water (SDW). The potential for transfer of pathogens from contaminated peppers to other non-contaminated produce items, and the effect of knife disinfection in preventing this cross contamination, were also tested. Knife disinfection procedures were evaluated by chopping inoculated peppers into 1 cm² pieces with kitchen knives. Experimental knives were then treated by either no treatment (control), wiping with a dry sterile cotton towel, rinsing under running warm water for 5 or 10s, or applying a 1% (v/v) lauryl sulfate-based detergent solution followed by rinsing with warm running water for 10s. Following disinfection treatment, knives were used to slice cucumbers. Exposure to H₂O₂ for 5 min and EtOH for 1 min resulted in reductions of 1.3±0.3 log₁₀ CFU/cm² for both pathogens. A 5 min exposure to AA resulted in a reduction of S. enterica of 1.0±0.7 log₁₀ CFU/cm² and E. coli of 0.7±0.8 log₁₀ CFU/cm². No differences (p ≥ 0.05) were found between numbers of pathogens on knives and numbers of pathogens transferred to cucumber slices, suggesting that organisms remaining on knife surfaces were transferred to cucumbers during slicing. Findings suggest that EtOH and H₂O₂ may be effective antimicrobials for in-home decontamination of peppers, and that use of detergent and warm water is effective for decontamination of implements used during meal preparation.