Lettuce (Lactuca sativa) handling features and coliform levels in markets of Maputo City

Abstract

Markets from Maputo City have been reported to have poorly hygienic premises and sellers unaware of the safest food handling practices. This study aimed to analyze associations between some lettuce (Lactuca sativa) handling features and the levels of total, fecal coliforms and Escherichia coli. Cabbage was purchased in the 3 markets. Just before the acquisition, the researchers recorded the source of water used to wash it, if they were sold in booths or on the floor, if they were sold mixed with other products, and if the sellers were wearing gloves. The cabbage heads (42) were analyzed through the technique of multiple tubes to estimate the most probable number. Average levels were 14.43 MPN/g for total coliforms, 13.9 MPN/g for fecal coliforms and 12.02 MPN/g for E. coli. The highest levels of contamination seemed associated with the use of well water, the food sold on the floor, the lettuce sold together with other products and the lack of gloves. The mixture of products only showed a major impact on the level of E. coli (p < 0.001). Yet, all levels were within the satisfactory range, according to the guidelines from The International Commission on Microbiological Specifications for Foods (ICMSF).

Handling of Fresh Vegetables: Knowledge, Hygienic Behavior of Vendors, Public Health in Maputo Markets, Mozambique

“…These waters have not been treated as recommended, as reported by Matangue et al [ 8 ], who showed that these irrigation waters were contaminated with pathogenic bacteria and Giardia spp. Cambaza et al [ 22 ] reported the occurrence of high levels of fecal coliforms and Escherichia coli in lettuce sold in Maputo markets, probably from this producing area. Some authors emphasize that wastewater discharged from farms cannot be neglected because they are considered as an important source of water pollution, including intestinal pathogens (e.g., E. coli , G. duodenalis and Cryptosporidium spp.…”

“…Meanwhile, the way products are washed and the use of the same containers to wash all vegetables increase the possibility of contamination [ 37 ]. To reduce contamination, water must be changed frequently [ 22 ] and the containers also need to be disinfected frequently.…”