1. Food Engineering Division, National Food Research Institute, Tsukuba 305-8642, Japan, Research Center of Advanced Bionics, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8565, Japan, Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan, and Department of Materials, ETH-Zürich, CH-8093 Zürich, Switzerland