1. Food Technology Program, Faculty of Science, Mahidol University, Kanchanaburi, Thailand.
2. Department of Biotechnology, Faculty of Science, Mahidol University, Bangkok, Thailand.
3. Whistler Center for Carbohydrate Research, Purdue University, West Lafayette, IN 47907.
4. Corresponding author. Phone: 1-765-494-5684. Fax: 1-765-494-7953. E-mail: bemiller@purdue.edu