1. 1Department of Food Science and Technology, College of Engineering, Ewha Womans University, Seoul 120-750, Korea
2. 2Department of Chemical Engineering and School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang 790-784, Korea
3. 3Institute of Life Sciences and Resources and Graduate School of Biotechnology, Kyung Hee University, Suwon 449-701, Korea