Distribution of chlorinated pesticides in soybeans, soybean oil, and its by‐products during processing

Soybean samples were collected from seven different locales in Central Illinois and subjected to analysis for chlorinated pesticides. Different parts of the beans showed varying levels of residue concentrations. It was found that pesticide residues had a tendency to accumulate, in descending order, in hypocotyls, hulls and cotyledons on the basis of ground samples. When oils extracted from the same fractions were analyzed, much higher concentrations of residues were located in hulls than hypocotyls, which had greater concentrations than cotyledons. Crude, refined, bleached and deodorized oils, soapstock, Fuller's earth sludge and deodorization condensate swere analyzed for hexachlorobenzene isomers, heptachlor, heptachlor epoxide, aldrin, dieldrin, DDT, DDD and DDE. None of the processing steps except deodorization were completely effective in the removal of chlorinated pesticide residues. Oil deodorized at 250 C under 1‐5 mm pressure was almost free of such residues, whereas all the residues were concentrated in deodorization condensate.