evaluating the efficiency of the common method of lettuce disinfection in iran

background: raw vegetables are particularly susceptible to microbial growth and, therefore, use of an effective sanitizer on these food items is of great importance. the objective of this study was to evaluate the efficacy of the vegetable disinfection protocol set forth by iranian ministry of health in reducing populations of total coliform, fecal coliform, and parasites present on lettuce. methods: in the present study, we determined the load of total coliform, fecal coliform, and parasites of lettuce obtained from market in tehran, iran. the lettuce was sanitized by the protocol of iranian ministry of health. the protocol consists of 3 levels to disinfection of fruits and vegetables. firstly, all fruits and vegetables should be completely washed in water. secondly, all parasites should be removed from vegetables by 3 to 5 drops of detergent per liter for approximately 5 minutes. finally, disinfectants (200 ml/l), especially chlorine, should be applied on vegetables for approximately 5 minutes. findings: the average initial levels of total coliform and fecal coliform in the samples were 3.36 log 10 cfu/g and 2.31 log 10 cfu/g, respectively. parasites were not detected in any of the samples tested. after washing, the efficiency of total coliform and fecal coliform removal were 78.1% (0.75 log 10 cfu/g) and 79.6% (0.67 log 10 cfu/g), respectively. the rates increased to 94.8% (1.44 log 10 cfu/g) and 98.5% (1.90 log 10 cfu/g) after the use of detergents. chlorine disinfection rose these amounts up to 98.3% (2.18 log 10 cfu/g) and 100% (2.31 log 10 cfu/g), respectively. by applying the protocol set by the iranian ministry of health, which has been developed for disinfection of vegetables, large parts of microorganisms existing on lettuce had indeed been removed. however, additional studies need to be conducted to determine the effectiveness of chemical treatments in the sanitation of raw vegetable. conclusion: instructions of the ministry of health can be used as an effective method to disinfect in vegetables since it removes 98.3% of total coliforms and 100% of fecal coliforms on lettuce.