1. Institute of Food Science and Technology, Taipei 106, Taiwan
2. Biologics Division, Animal Health Research Institute, Council of Agriculture, Executive Yuan, New Taipei 251, Taiwan
3. Metal Industries Research and Development Centre, Kaohsiung 811, Taiwan
4. Department and Institute of Veterinary Medicine, School of Veterinary Medicine, National Taiwan University, Taipei 106, Taiwan
5. Department of Chemistry, National Taiwan University, Taipei 106, Taiwan