1. Department of Pathology, Medical Biology and Immunoendocrinology, Division of Medical Biology University Medical Center Groningen Hanzeplein 1, 9713 GZ Groningen The Netherlands
2. Laboratory of Food Chemistry Wageningen University Bornse Weilanden 9, Wageningen WG 6708 The Netherlands
3. Department of Applied Life Science, Faculty of Applied Biological Sciences Gifu University 1‐1 Yanagido Gifu City 501‐1193 Japan
4. DSM Biotechnology Center Alexander Fleminglaan 1 Delft AX 2613 The Netherlands