1. Department of Food Technology, University of Helsinki, POB 27, 00014 University of Helsinki, Finland.
2. Department of Food Technology, Kaunas University of Technology, Radvilenu plentas 19, 3028 Kaunas, Lithuania.
3. Corresponding author. E-mail: Tuula.Sontag-Strohm@helsinki.fi Phone: 358-9-191-58230. Fax: 358-9-191-58463.