Effect of Different Household Decontamination Procedures on Antioxidant Activity and Microbial Load of Vegetables

Document Type : Original Article


1 Environmental Health Engineering Department, School of Public Health, Tehran University of Medical sciences, Tehran, Iran

2 Environmental Health Engineering Department, School of Public Health, Neyshabur University of Medical Sciences, Neyshabur, Iran


Aims: Decontamination procedures are different in each country, as the other
applications of disinfection, and standards. The aim of this study was to
evaluate the effects of household decontaminations and storage time on the
antioxidant activity and microbial load of salad vegetables.
Instrument & Methods: This analytic-descriptive study was conducted on 4
types of salad vegetables; cucumber, tomato, lettuce, and sweet basil. After
washing, samples with storage time of 0 day were analyzed immediately. Other
samples were held in 4°C for 3 and 5 days. Five different washing and
decontamination methods were compared; water washing, detergent washing,
benzalkonium chloride, sequential washing and Kanz disinfecting method. The
Ferric Reducing Ability of Plasma assay was used to measure the antioxidant
activity. Aerobic mesophyll bacteria and total coliforms were chosen as
microbial load index. ANOVA and Tukey post-hoc tests were used to analyze the
Findings: By increasing the storage time, the antioxidant activity of all types of
vegetables reduced. There was a significant decrease in antioxidant activity in
all types of vegetables using sequential washing method with water, detergent,
and benzalkonium chloride and Kanz disinfection method. All washing methods
were effective in decontamination for either mesophyll bacteria or total
coliforms, except for total coliforms in lettuce. There was no significant
difference in microbial load among first 4 methods of washing (p>0.05), but a
significant difference was observed in Kanz disinfection method (p<0.05).
Conclusion: Kanz disinfection is the most effective decontamination method to
eliminate microorganisms index, which also reduce the antioxidant activity.