1. Federal Center for Meat Research, Institute of Microbiology and Toxicology, E.-C.-Baumann-Strasse 20, D-95326 Kulmbach, Germany; Budapest University of Technology and Economics, Institute for General and Analytical Chemistry, NMR Group, Szent Gellért tér 4, H-1111 Budapest, Hungary; and University of Münster, Department of Food Chemistry, Corrensstrasse 45, D-48149 Münster, Germany