Cereal Chem 54:1229 - 1237. | VIEW
Alcohol Treatment of Soybeans and Soybean Protein Products.
A. C. Eldridge, K. Warner, and W. J. Wolf. Copyright 1977 by the American Association of Cereal Chemists, Inc.
Earlier studies suggest that some undesirable flavors of soybeans and soybean products result from enzymatic oxidation of unsaturated lipids and subsequent breakdown of the hydroperoxides formed. Such enzyme action is believed to occur as soon as the seed is crushed. To test this hypothesis, soybeans and soybean protein products were steeped or wet-milled with aqueous ethyl alcohol at 25 C to inactivate enzymes in situ or as soon as the cellular structure is disrupted. The treated materials were dried at reduced temperatures and pressures and then assayed for lipoxygenase, urease, and trypsin inhibitor activities. Nitrogen solubility indexes and organolepic properties were also determined. When aqueous alcohol was used in a concentration range of 40 to 60% (v/v), exzymatic activities and nitrogen solubility indexes were reduced extensively, but trypsin inhibitor was only partially inactivated. Flavor evaluation indicated improved products, i.e., the characteristic beany, bitter flafor of untreated soybeans was reduced in materials treated with aqueous alcohol. The flavor of other raw legumes, including lima beans, split peas, black-eyed peas, and peanuts, also improved after a similar aqueous alcohol treatment.