Isolation of a rich glucosinolate fraction by liquid chromatography from an aqueous extract obtained by leaching dehulled rapeseed meal (Brassica napus L)

Concurrent with biogenetic research to discover new cultivars of rapeseed with a low level of glucosinolates tan antinutritional factor), the aim of this study was to valorize an aqueous extract that was obtained by leaching dehulled rapeseed meal in order to eliminate the glucosinolates (GSL). The rapeseed meal used (Brassica napus L. var oleifera; cultivar 'Darmor') contained 50.6 mmol g(-1) of GSL. A method has been developed to produce a GSL fraction containing especially the two major GSLs: progoitrin and gluconapin. Until now, it has not been possible to synthesize progoitrin by chemical means and it is not available on the market, which makes it difficult to study its potentialities. Each parameter of the method, based on the adsorption of the compounds of an extract on an acidic alumina column, was studied and defined for production on an industrial scale. The method allows a rich fraction of GSL to be obtained with 93% yield from the initial GSL extract. This fraction contains, by weight, 29% GSL, 3% KNO3 and 63% KCl, only 5% of the total of the dry matter remains unidentified. (C) 1998 Elsevier Science B.V. All rights reserved.