1. Korea Food Research Institute, San 46-1, Backhyun, Bundang-gu, Sungnam, Kyonggi-do 463-746, Korea, Department of Neuroscience, College of Medicine, Ewha Woman's University, 911-1 Mok-6-dong, Yangchun-ku, Seoul 158-710, Korea, and Department of Food and Nutritional Sciences, Ewha Womans University, 11-1 Daehyun-dong, Seodaemun-ku, Seoul 120-750, Korea