Abstract
Lettuce is a vegetable most consumed worldwide. However, when not properly sanitized, it can cause various foodborne illnesses. Thus, this research aimed to verify the knowledge of handlers regarding the washing and disinfection of vegetables, as well as to evaluate the efficiency of different processes of washing and disinfection of lettuce (Lactuca sativa) sold in supermarkets. A questionnaire was applied to consumers to know the practices used for washing and disinfecting vegetables. After, 100 samples of lettuce were purchased in different supermarkets. To evaluate the microbiological quality of lettuces we used: lettuce without treatment (T0); washing with running tap water (T1); immersion in treated water for 30 minutes (T2); immersion in sodium hypochlorite at 200 ppm for 15 minutes (T3); and 30 minutes (T4); immersion in 2% vinegar solution (T5); immersion in 20% vinegar solution (T6); immersion in sodium hypochlorite at 50 ppm for 30 minutes (T7); and 15 minutes (T8). After the treatments, we performed a total count of heterotrophic bacteria and thermotolerant coliforms. The mean heterotrophic bacteria count found before sanitation (T0) was 5.54 log UFC/g. Most consumers say they only wash lettuce with water and only 7.50% disinfect. In 56.3%, the consumers are not aware of the correct way to clean vegetables. All methods used were able to reduce heterotrophic bacteria counts and the best reductions were presented respectively by treatments T4 (2.27 log UFC/g) and T3 (2.09 log UFC/g). None of the samples showed thermotolerant coliforms contamination before and after cleaning. These results allow us to conclude that lettuce washing and disinfection methods are necessary to reduce microbial contamination in this food before consumption and that it is necessary to guide consumers of the importance of this practice.
Keywords:
Leafy vegetable; Heterotrophic bacteria; Coliforms; Contamination; Sanitation; Handlers
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