Selective extraction, structural characterisation and antifungal activity assessment of napins from an industrial rapeseed meal

This article reports an extraction-purification of napins from an industrial rapeseed meal and the assessment of their antimicrobial activity against Fusarium langsethiae. The best extraction conditions are observed at pH 2, 12% (w/w) of rapeseed meal after 15 min of extraction in water at room temperature. Under these conditions the extraction is highly selective, allowing a simple purification process (ammonium sulfate precipitation followed by desalting size exclusion chromatography) to get purified napins. These napins possessed significant anti-Fusarium activity (IC50 = 70 mu m) and a compact secondary structure rich in a-helix, which may explain this bioactivity. (C) 2012 Elsevier Ltd. All rights reserved.