Evaluation of the effectiveness of bleach on microbial population of lettuce
Keywords:
Lettuce, bleach, efficiency, disinfection, concentration of microbial populationAbstract
The effectiveness of bleach on the microbial population of lettuce was evaluated. Microorganisms on lettuce before and after washing with bleach were searched and counted and a new dose for cleaning to eliminate a high concentration of bacteria on the lettuce has been proposed to minimize the health risk linked to its consumption. The lettuce samples were collected from farms municipalities V and VI of the District of Bamako. Ten lettuces were collected from different plots and mixed to form a composite sample. The concentration of microbial population was determined by finding and counting the total microflora in 100g of lettuce composite sample before and after washing with bleach different chlorine concentrations for different contact times. Lettuces grown in Bamako are heavily contaminated with microbial population average between 25 to 1363UFC / g of lettuce. The application of the recommended dose of chlorine (133.10-5mg / l) in Mali for the disinfection of fruits and vegetables for 15, 30 and 60 min resulted in a drawdown respectively 94%, 97% and 99% of the initial microbial population lettuce. The recommended dose and double dose of this leading to high rates of drawdown of 97% and 99% of the initial microbial population of lettuce. 1% of the concentration of microbial population remains on the treated leaves. Dose which totally eliminates the microflora is 2.6 mg / l of chlorine applied for fifteen minutes. The new dose we can offer is the application of 2.6 mg / l of active chlorine.Keywords: Lettuce, bleach, efficiency, disinfection, concentration of microbial population.
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