1. Department of Food and Nutrition, Seoul National University, 599 Gwanak-ro, Gwanak-gu, Seoul 151-742, Korea.
2. School of Hospitality Management, Pennsylvania State University, University Park, PA 16801, USA.
3. Research Institute of Human Ecology, Seoul National University, 599 Gwanak-ro, Gwanak-gu, Seoul 151-742, Korea.