1 University of Hamburg, Hamburg School Of Food Science, Institute of Food Chemistry, Grindelallee 117, D-20146 Hamburg, Germany; Leibniz-Institute of Vegetable and Ornamental Crops, Großbeeren/Erfurt e.V., Department of Quality, Theodor-Echtermeyer-Weg 1, D-14979 Großbeeren, Germany.
2 University of Hamburg, Hamburg School Of Food Science, Institute of Food Chemistry, Grindelallee 117, D-20146 Hamburg, Germany.
3 Leibniz-Institute of Vegetable and Ornamental Crops, Großbeeren/Erfurt e.V., Department of Quality, Theodor-Echtermeyer-Weg 1, D-14979 Großbeeren, Germany.
4 University of Hamburg, Hamburg School Of Food Science, Institute of Food Chemistry, Grindelallee 117, D-20146 Hamburg, Germany. Electronic address: rohn@chemie-uni-hamburg.de.