Soybean (Glycine max L.) storage proteins have two major fractions, β-conglycinin (7S) and glycinin (11S),accounting for more than 70% of the total protein (Tsukadaet al. 1986), and their contents have been shown to vary among soybean varieties and environmental conditions (Hughes and Murphy 1983; Murphy and Resurreccion 1984;Saio et al. 1969; Wolf et al. 1961).