1. H.&J. Brüggen KG, Lübeck, Germany
2. Division of Food Technology, Institute of Human Nutrition and Food Science, Kiel University, Kiel, Germany
3. Division of Plant Diseases and Crop Protection, Institute of Phytopathology, Kiel University, Kiel, Germany
4. GBA Gesellschaft für Bioanalytik mbH, Hamburg, Germany