1. Department of Health Food Science, Chungkang College of Cultural Industries, San 37, Haewol-Li, Majang-Myun, Ichon 467-840, Korea.
2. Department of Biotechnology, Yonsei University, Shinchon-Dong, 134, Seodaemun-Gu, Seoul 120-749, Korea.
3. Corresponding author. Fax: 82-2-312-6821. Phone: 82-2-361-2883. E-mail: yrpyun@yonsei.ac.kr