1. Department of Food Science; University of Parma; Viale delle Scienze 95a I-43124 Parma Italy
2. Interdipartimental Center for Measurements; University of Parma; Viale delle Scienze 23a I-43124 Parma Italy
3. Mass Spectrometry Center (CISM); University of Firenze; Viale G. Pieraccini 50139 Firenze Italy