IUPAC REPORTS ON PESTICIDES .31. EFFECTS OF STORAGE AND PROCESSING ON PESTICIDE-RESIDUES IN PLANT-PRODUCTS

Residues of pesticides in food are influenced by the storage, handling and processing that occurs between harvesting of raw agricultural commodities and consumption of prepared foodstuffs. Reviewing the extensive literature showed that in most cases these steps lead to large reductions in residue levels in the prepared food, particularly through trimming, washing and cooking operations. Residues of post harvest insecticide treatment on stored staples such as cereal grains and oil seeds generally decline only rather slowly. However processing into foods again results in large losses except for unrefined oils. The behaviour of residues in storage and processing can be rationalised in terms of the physico-chemical properties of the pesticide and the nature of the process. EBDC fungicides are examined in more detail as a class of fungicides of concern due to the formation of the toxic breakdown product ETU. Recommendations are provided for the conduct of storage or processing studies on fate of pesticide residues in food so that data obtained is relevant, comparable and may be extrapolated to other situations.