According to the method of Guo, Ono, and Mikami (1999), p. 11 mL of soymilk was separated into floating fraction, soluble fraction, and particulate fraction by centrifugation at 156, 000 for 30 min at 20 C. The floating fraction in the top layer and particle fraction in the bottom layer were carefully collected and washed with distilled water for three times and dispersed with 11 mL ultrafiltrate by a tissue grinder (Wheaton, NJ, USA) for 10 min. The soluble fractionwas directly adjusted to a volume of 11 mL by using ultrafiltrate. The particulate, soluble, and floating fractions were lyophilized and stored in the refrigerator at 4 C before use.