Oilseed pretreatment in connection with physical refining

Tests have shown that the nonhydratable phosphatides (NHP) arising by the action of phospholipases are not present in significant quantities in commercial soybeans, but that they are formed predominantly only during extraction. By a moisture-heat treatment of the soy flakes prior to the extraction, this enzyme activity can be almost completely eliminated so that, during the subsequent extraction, an enzymatic change of the oil no longer occurs. In comparison with the extraction of untreated soy flakes, the yield of soy lecithin is doubled; the lecithin has a higher content of phosphatidylchol ine; the crude, degummed soy oil has extraordinarily low NHP contents; and the soy meal tastes less bitter.