Lipoxygenase-oxidized soap stock as source of hydroxy conjugated octadecadienoic acids

A laboratory procedure was developed for the production of hydroxy conjugated octadecadienoic acids (HOCD). Lipoxygenase oxidation of distilled or crude soap stock produces hydroperoxy conjugated octadecadienoic acids, which can be reduced to HOCD. Crude aqueous soy flour extracts and defatted soy flour are convenient, effective and inexpensive lipoxygenase sources. This new procedure allows high substrate concentrations of 100 mg/ml to be used while achieving 75% to 90% oxidation of the available linoleic acid during a reaction time of 20 to 40 min. Aqueous ethanol and dimethyl sulfoxide (DMSO) solvent systems were compared. The DMSO system produced higher yields of hydroperoxy acids with low enzyme concentrations. Hydroperoxide yields are good when short reaction times, high pH levels and free radical scavengers are used. Presented at the AOCS Meeting, Chicago, September 1970. No. Utiliz. Res. Dev. Div., ARS, USDA.