1. Department of Food Science, Eulji University, Gyeonggi 461-713, Korea.
2. Division of Tourism Information Management, DongSeoul University, Gyeonggi 461-714, Korea.
3. Department of Food & Nutrition, College of Health Sciences, Korea University, Seoul 136-703, Korea.
4. Department of Food & Nutrition/Health Sciences Research Institution, College of Health Sciences, Korea University, San-1 Jeongneung-dong, Seongbuk-gu, Seoul 136-703, Korea.