Agricultural and Biological Research

Pesticide, trace metal and microbiological analyses of open field and greenhouse-harvested crops from Trinidad before and after processing

Rohanie Maharaj*, Farrah Mathura and Inteaz Alli

Greenhouse-grown crops are generally considered safer than open field crops. The study objectives were to determine whether greenhouse-grown crops in Trinidad were safer than open field crops by monitoring microbiological, trace metal and pesticide levels via a “farm-to-fork” approach. Open field tomatoes were compared to those grown in greenhouses over a two-year period. Additionally, greenhouse-grown tomatoes and sweet peppers from the university experimental station were analyzed for food safety. Quantitative analyses were based on the presence of 45 pesticide residues, trace metals (lead and cadmium) and microbiological contaminants (faecal coliforms, Staphylococcus aureus and Salmonella sp.). Meals prepared from open field tomatoes in year 2 were analyzed for food safety. Neither greenhouse-grown crops (tomatoes and sweet peppers) nor open field tomatoes had a hazardous quantity of the microbes screened or trace metals, except for a batch of open field tomatoes that contained 0.12 mg/kg lead. Eight pesticides (profenofos, ethion, lambda cyhalothrin, cypermethrin, bifenthrin, iprodione, permethrin, and endosulfan) detected in both the open field and greenhouse-grown crops over a two-year period were present below the EU and Codex MRLs, except for a batch of the university experimental station greenhouse-grown tomatoes and sweet peppers, which exceeded the Codex MRL for lambda cyhalothrin. More pesticides were found in year two due to possible additive effects. Meals prepared using tomatoes posed no health risk to children. Overall, the quality of the open field and greenhouse crops was acceptable for consumers, but annual monitoring of these parameters can assure food safety.