1. Laboratory of Industrial Chemistry, Process Chemistry Centre, Department of Chemical Engineering, Faculty of Technology at Åbo Akademi University, Biskopsgatan 8, FI-20500 Turku, Finland, Department of Applied Physics, University of Turku, Vesilinnantie 5, FI-20014 Turku, Finland, and Danisco Sweeteners, Sokeritehtaantie 20, FI-02460 Kantvik, Finland