LIPIDS EXTRACTED FROM SOY PRODUCTS BY DIFFERENT PROCEDURES

Lipids in soybean defatted meal, concentrate and isolate were extracted by four procedures: (a) a Soxhlet extract by chloroform-methanol; (b) a Soxhlet extraction by benzene/ethanol; (c) a short extraction by chloroform/methanol; and (d) a short extraction by hexane/ethanol. Procedure 2 extracted more lipid than Procedure 1 from the isolate and meal. Both Soxhlet procedures extracted more lipid than Procedure 3 from the meal only, and more lipid than Procedure 4 from all products. Percent lipid on dry matter basis ranged for the meal, 1.56 to 4.52; concentrate 0.90 to 1.44; and isolate, 0.28 to 0.96. Lipids extracted from each product by Procedures 3 and 4 were fractionated quantitatively into (a) neutral lipids, (b) polar lipids except lecithin, and (c) lecithin. Fatty acid (C12-C20) composition of each lipid fraction was determined, and attempts were made to identify lipids. The larger amount of lipid in any product extracted by either Procedure 3 or 4 was in Fraction 1. Linoleic acid was the most abundant acid found in any lipid fraction. Significantly more oleic acid was found in Fractions I and II Concentrate lipids than in the same fractions of meal or isolate lipids. A number of lipids were found in Fractions I and II, but the only lipid in Fraction III was lecithin. © 1979 The American Oil Chemists' Society.