SURVEY AND COMPARISON EFFICACY OF ALKYL DIMETHYLBENZYL AMMONIUM CHLORIDE AND BENZALKONIUM CHLORIDE AND CHLORINE IN REDUCING OF MICROBIAL LOAD OF LETTUCE

Because of application human and animal manure, polluted water and contact of
animals in farms, Fruits and vegetables generally are contaminated with patogens. So, to removal of
these contaminants, vegetables must be decontaminated before used. In this study, efficacy of two
widely used disinfectants (Alkyl Dimethylbenzyl Ammonium Chloride and Benzalkonium chloride) in
reduction of microbial load of lettuce were studied and also we comprise these to chlorine in the form
of Calcium hypochlorite in order to reassure the people that used these disinfectants.
Materials & Methods: In the present study, we determined the microbial load reduction in four steps
of sanitizing and disinfection of lettuce obtained from market in Urmia (application of Alkyl
Dimethylbenzyl Ammonium Chloride and Benzalkonium chloride and chlorine) and we used Most
Probable Number of coliform (MPN) index to determined efficiency of washing and disinfection in
reduction of microbial load.
Results: Results of this study show that, average initial levels of total coliform in lettuce obtained
from market in Urmia samples were 3.557 log10 CFU/g. After disinfection of lettuce according to the
protocol of Iranian Ministry of Health, at step of completely washed in water after cleaning average
levels of total coliform were decreased to 3.35 log10 CFU/g and at step of washing with detergent,
total coliform reduced to 2.07 log10 CFU/g. At step of disinfection with chlorin, initial microbil load
decreased to 0.9 log10 CFU/g and Benzalkonium chloride caused decreased initial microbial load to
1.8 log10 CFU/g and Alkyl Dimethylbenzyl Ammonium Chloride caused decreased initial microbial
load to 1.6 log10 CFU/g.
Conclusion: Chlorin is an effective disinfectant in disinfection of lettuce that caused decrased 2.6
log10 CFU/g of colifrm at lettuce, and have beter efficiency than other two commertial disinfectants.