NEUROTOXINS IN A VETCH FOOD - STABILITY TO COOKING AND REMOVAL OF GAMMA-GLUTAMYL-BETA-CYANOALANINE AND BETA-CYANOALANINE AND ACUTE TOXICITYFROM COMMON VETCH (VICIA-SATIVA L) LEGUMES

Because the neurotoxic common vetch (Vicia sativa L.) legume seems to have come into some use in man's diet, we have investigated, using Pic o-Tag analysis, the stability of the vetch neurotoxins to cooking. Whe n heated in water at 100 degrees C for 3 h, gamma-glutamyl-beta-cyanoa lanine (gamma-gluBCA) cyclized extensively to form pyroglutamic acid a nd beta-cyanoalanine (BCA). By contrast three specimens of common vetc h seeds containing 0.42-0.74% gamma-gluBCA and 0.01-0.03% BCA retained these principles without loss. A modified cooking procedure replacing the broth during cooking with fresh water and washing the seeds well yielded cooked seeds without detectable neurotoxins. A nutritional stu dy confirmed that the toxins responsible for causing weight loss and m ortality in chicks were removed. Lengthy steeping in water at room tem perature also effectively removed the neurotoxins from dehulled split seeds but incompletely from intact seeds. These procedures improve the quality of common vetch seed as a source of protein for man.