Heavy metals ranks high amongst the chief contaminants of leafy vegetables and medicinal plants. Poisoning from heavy metal contamination of medicinal plant products has caused countless health implications including liver and kidney failure and even death. Several methods for determination of Se have been developed for many years. However, cooking may affect antioxidant content due to antioxidantrelease, destruction or creation of redox-active metabolites. Plants can amass trace elements, especially heavy metals, in and on their tissues due to their ability to tolerate potentially toxic ions in the environment. However, cooking may affect antioxidant content due to antioxidant release, destruction or creation of redox-active metabolites. However, this drying process is slow and metabolic processes may continue longer which may lead to quality loss of the plants and subsequently to the extracts, e.g. colour changes, loss in active ingredients.
