The 7S and 11S globulins are major components of soybean protein. A novel freeze-thaw method for simplified fractionation of these proteins in soymilk has been developed. Raw soymilk was frozen at -30°C, and then thawed at 10°C for 24 h. The freeze-thawed soymilk was separated into two layers, and the weight ratio of the upper layer to the lower layer was 3:2. In SDS-PAGE analysis, the 11S/7S ratios were 0.14 and 1.7 in the upper and lower layers, respectively. Tofu curds were prepared using various ratios of the upper to lower layers. The breaking stress of the tofu curd increased with the increase of the lower layer. The curd made from the upper layer was soft and smooth, whereas that made from the lower layer was firm. A novel dessert-like product was made from the upper layer and a novel sausage-like product was made from the lower layer. These results show that rough separation of 7S and 11S globulins in raw soymilk can be achieved using a simple freeze-thaw treatment, thus facilitating the development of new food products.
