Arch Public Health 2010, 68 (Supplement 2), S57 Determination of bioactive compounds in leek (Allium ampeloprasum var. porrum) by Bernaert N1,2, Van Droogenbroek B1, Van Bockstaele E1,2, Stewart D3, De Loose M1,4 Leek (Allium ampeloprasum var. porrum) is in Flanders one of the most important crops cul- tivated outdoors. But, it is a product with a rather old fashioned and traditional image, as well on the mode of commercializing as on the mode of use. This research project aims to create innovation and market growth by analyzing specific bioactive compounds in leek like flavon- oids, organosulfur compounds and inulin. Before analyzing this specific compounds, we started with the Oxygen Radical Absorbance Capacity (ORAC) assay for analyzing the anti- oxidant capacity in 34 leek varieties and 6 related species. The antioxidant capacity in the green part of leek was significant higher in most varieties in comparison with the white part. Related species like shallot also showed a significant higher ORAC value. In a later phase the influence of processing techniques on the content of these compounds will be analyzed, what can result in suggestions for improved processing methods with a maximal preservation of the desired compounds. Analyses of flavonoids and organosulfur compounds will be done using high performance liquid chromatography tandem mass spec- trometry. The determination of inulin on the other hand will be accomplished with the help of high performance liquid chromatography with refractive index detector. The knowledge built up around bioactive compounds in leek will be communicated to research/practice centers, breeding stations and other interested parties. Keywords Allium ampeloprasum var. porrum, bioactive compounds, genetic diversity, innovation, leek, ORAC 1 University of Ghent, Department of Plant Production, Coupure Links 653, 9000 Ghent, Belgium 2 Institute for Agricultural and Fisheries Research (ILVO), Unit Technology and Food (T&V), Research group Product quality and innovation, Merelbeke, Belgium 3 Scottish Crop Research Institute (SCRI), Dundee, United Kingdom 4 University of Ghent, Department of Molecular Genetics, Ghent, Belgium [email protected] .