1. Beijing Engineering Research Center of Protein & Functional Peptides, China National Research Institute of Food & Fermentation Industry, Bldg. 6, No. 24, Jiuxianqiao Middle Road, Chaoyang District, Beijing 100015, P. R. China
2. Graduate School of Applied Biosciences, Kyoto University, Kitashirakawa Oiwake-cho, Kyoto 606 8502, Japan