1. Section of Industrial and Food Chemistry, Department of Chemistry, University of Ioannina, 45110-Ioannina, Greece, General Chemical State Laboratory, D'Chemical Services of Pireaus, Akti Kondyli 32, 18510 Pireaus, Greece, Department of Petroleum Technology, Technological Educational Institute of Kavala, 65404-Kavala, Greece, and Department of Food Technology, Technological Educational Institute of Athens, Ag. Spyridonos Str., 12210 Egaleo, Athens, Greece