Characterization of Soymilk Prepared by Milling and Pressing at High Temperature
The effect of milling and pressing soybeans at high temperatures (50–90C) was examined for laboratory-scale soymilk preparation. Soymilk that was milled and pressed at high temperatures showed more precipitate and a slightly lower protein content. The surface sulfhydryl content and surface hydrophobicity of the soymilk protein increased with milling temperature, which indicates some acceleration of the thermal denaturation of proteins. Ultracentrifugation and laser diffraction particle size analysis of the soymilk showed that milling at 90C resulted in highly dispersed protein aggregates and emulsions.

Practical Applications
Processing method for soymilk was improved to decrease beany flavor derived from lipoxygenase. Now soybean is milled at high temperatures to inactivate lipoxygenase activity, but there are no useful data on the quality of the resulting soymilk. In this study, milling at 90C showed more disperse soymilk than at 80C by considering droplet size distribution and protein denaturation behavior. These data are useful for estimation of the quality of soymilk beverage and for improvement of soymilk processing for more palatable beverages.