1. Department of Bioscience and Engineering, Shibaura Institute of Technology, 307, Fukasaku, Minuma-ku, Saitama, Saitama 337-8570, Japan
2. Food Research Institute, National Agriculture and Food Research Organization, 2-1-12, Kannondai, Tsukuba, Ibaraki 305−8605, Japan
3. Nagano Prefectural Fruit Tree Experiment Station, 492 Ogawara, Suzaka-shi, Nagano 382−0072, Japan