Cereal Chem 46:145 - 155.  |  VIEW ARTICLE
Biological Evaluation of Crambe Seed Meals and Derived Products by Rat Feeding.

C. H. Van Etten, W. E. Gagne, D. J. Robbins, A. N. Booth, M. E. Daxenbichler, and I. A. Wolff. Copyright 1969 by the American Association of Cereal Chemists, Inc. 

Diverse hydrolytic reaction products have been identified that are derived from the major crambe seed thioglucoside, epi-progoitrin (e-PG), and the responsiveness of the reaction pathway to controllable environmental factors has been clarified. The principal product of thioglucoside breakdown by thioglucosidase(s) in crambe meal is either a mixture of three nitriles, the oxazolidinethione (R)-goitrin, or some combination of these substances. Such elucidation of products from thioglucosidase activity has made it possible to prepare for rat-feeding studies definitively characterized crambe meals, as well as compounds or fractions of known chemical composition derived from them.Inclusion of 0.23% (R)-goitrin in rat diets decreased growth to 85% of that of a control group. A mild hyperplastic goiter and a mild degenerative nonspecific alteration of liver cells were the only microscopic changes detected. Similar growth restriction resulted when comparable levels of e-PG were fed, incorporated into the diet either as an isolate or in a crambe meal in which thioglucosidase enzyme(s) had been inactivated. In contrast, either autolyzed meal that contains the nitrile mixture, or the nitrile mixture itself after isolation from the meal by extraction, was more harmful. Both caused poorer growth or death, and resulted in bile-duct hyperplasia, fibrosis, and megalocytosis of hepatocytes and tubular epithelial cells in the kidney. Rats fed meal containing intact e-PG plus active thioglucosidase enzyme(s) had similar but milder lesions than did rats fed the nitrile mixture. Fibrosis was not observed; thyroid hyperplasia occurred.Protein efficiency ratios (PER) were determined on defatted crambe meals that had been made nontoxic by aqueous acetone extraction without use of elevated temperatures. The PER's of 2.75 and 2.55 were higher than that of casein (2.50).