1. Rothamsted Research, Harpenden, Herts AL5 2JQ, United Kingdom; Department of Applied Chemistry and Microbiology, University of Helsinki, P.O. Box 27, Latokartanonkaari 11, FI-00014 University of Helsinki, Finland; Agricultural Research Institute of the Hungarian Academy of Sciences, P.O. Box 19, 2462 Martonvásár, Hungary; Laboratory of Quality Evaluation of Plant Materials, Institute of Plant Breeding and Acclimatization, Radzikow PL-057870, Poland; Laboratory of Food Chemistry and Biochemistry, K. U....