THE ISOLATION OF HYDROXY-ACIDS FROM LESQUERELLA OIL LIPOLYSATE BY A SAPONIFICATION EXTRACTION TECHNIQUE/

The lipolysate from immobilized Rhizomucor miehei lipase (Lipozyme(TM) )-catalyzed hydrolysis of lesquerella oil contains typically 35% free fatty acid (FFA), 2% monoglyceride, 25% diglyceride (DC), and 38% trig lyceride (TC). Of the FFA, 75-80% are hydroxy acids (HFA). Various met hods for isolating HFA from the lipolysate were examined, and a novel saponification/extraction method was developed. Lipolysate was mixed w ith 4 vol equivalents each of KOH/phosphate buffer and polar organic s olvent. Hexane was then added to enhance phase separation. Three phase s formed: a lower aqueous phase containing nothing of interest, a pola r organic solvent middle phase that contained mostly fatty acid soaps, and a hexane-rich upper phase that contained mostly DG and TC, which can be recycled to a relipolysis step. The middle phase, when treated with concentrated hydrochloric acid, NaCl-saturated water, and hexane, released the FFA into the hexane. This fraction, referred to as the ' 'Product,'' contained >99% of the FFA released in the lipolysis. ''Pro duct'' consisted of 85-90% FFA, of which 75-80% was HFA. The other 10- 15% of the ''Product'' consisted of partial glycerides and TG. The mos t critical parameters for the extraction are the pH of the aqueous sol ution and the polarity of the organic solvent (acetone was found to be the best choice). Additional purification steps for the ''Product'' a re discussed.