A RAPID AND SIMPLE ASSAY FOR IDENTIFYING LOW GLUCOSINOLATE RAPESEED

Abstract

A rapid, simple and reliable method for the identification of seed from low glucosinolate cultivars of rapeseed (Brassica napus L. and B. campestris L.) was developed using a semi-quantitative, glucose-specific test paper containing glucose oxidase, peroxidase and the chromogen, o-tolidine. Glucose released from hydrolysis of the glucosinolates by the endogenous myrosinase in aqueous seed extracts was measured after removal of interfering substances with charcoal. Greater sensitivity at the lower end of the glucose test-paper range allowed identification of low glucosinolate seed from mixtures with normal glucosinolate seeds when the glucosinolate content of the mixture was double, or more, the content of the low glucosinolate seed. The stability of the reagents, sensitivity, simplicity and speed of the assay, approximately 5 min, suggest that it is suitable for the identification of low glucosinolate seed in commerce.