Development and application of a simple method to detect toxic chemicals in fruits and vegetables that can be implemented in a rudimentary laboratory setting: A proof of concept study

Many environmental chemicals are known to be present in or on food. In particular, low income countries can suffer from the application of mostly banned and toxic chemicals, combined with inappropriate usage, which can lead to high food contamination. To safeguard human health, residues in food are generally identified with targeted chemical analysis. There is increasing awareness of the need to assess the biological effects of mixtures of contaminants potentially present in food, but few studies have applied in vitro bioassays for monitoring chemicals in food. The present study aimed to combine a simple extraction method with bioanalytical testing of chemicals in food. Sensitive bioassays focusing on activation of the aryl hydrocarbon receptor (AhR) and bacterial toxicity were applied to detect the presence of chemicals. Liquid-liquid extraction, which was selected due to reduced solvent demand and rapid sample treatment, was applied to a range of food types. Additionally, extracted strawberry washing water was also tested to assess the impact of food preparation and cleaning. Regarding extraction efficiency, the method was more effective for high water content samples (e.g. strawberries, tomatoes) compared to fatty (e.g. fish, meat) and high fiber (e.g. apples) samples. Hence, greater effects were observed for watery samples in the studied assays, including a biological response with the washing water. Future work should focus on improvement of the liquid-liquid extraction method to address the urgent need of a simple but reliable hazard assessment tool of food for low income countries. •Liquid-liquid extraction and bioassays were applied to monitor chemicals in food.•Selected bioassays focused on both non-specific and specific modes of action.•Extraction method most applicable for watery food samples such as tomatoes.•Food bioanalytical monitoring approach proposed based on mixture toxicity modelling.