Crambe seed processing: Decomposition of glucosinolates (thioglucosides) with chemical additives

Abstract

Abstract Crambe meal was cooked with a variety of bases and metal salts to study decomposition of the undesirable glucosinolate (thioglucoside), epi ‐progoitrin. Salts of iron and copper were preferred because they were the most active decomposers and because they did not reduce the lysine content as did the alkalies. An unsaturated hydroxy nitrile, representing about 25 mole per cent of the decomposed epi ‐progoitrin, was the major reaction product left in the cooked meal. A thionamide product, representing about 7 mole per cent of the decomposed epi ‐progoitrin, was also observed in meals cooked with metallic salts. The thionamide was relatively unstable in moist, hot crambe meal, especially at basic pH, and may therefore be an intermediate in a complex decomposition path. Rats fed ferrous sulfate‐treated crambe meal as 30% of a protein sufficient diet gained 70% compared with a basal control. Enlargement of thyroid, liver and kidneys was about 1.5 times that of the control organs. A crambe meal heated under the same conditions but without ferrous sulfate and fed at the same diet level caused 100% mortality within two weeks.