The effect of soaking time on water absorption and solid losses of whole and dehulled soybeans

Dehulled entire soybean cotyledons are required for the preparation of many interesting products. Removing hulls had a dramatic effect on the rate of water uptake during soaking. Maximum uptake was reached in only 3 hr compared to the 12 hr needed by whole beans. This saves time and reduces microbial growth during soaking. The amount of water absorbed by beans, with and without hulls, was similar once corrected for solid losses and surface water. Removal of fibrous shells during dehulling increased both the protein and oil contents by 2 %. Dehulled beans steadily lost solids during soaking. Losses were 8.6 % compared to 0.7 % for whole beans when maximum uptakes were first reached. Ways of avoiding or reducing these losses are discussed.