Incorporation of γ-linolenic and linoleic acids into a palm kernel oil/palm olein blend

• Published in: European journal of lipid science and technology Vol. 107; no. 7-8; pp. 447 - 454
• Main Authors: Lumor, Stephen E., Akoh, Casimir C.
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01.08.2005; WILEY‐VCH Verlag; Wiley-VCH
• Subjects: Acidolysis; Biological and medical sciences; Fat industries; Food industries; Fundamental and applied biological sciences. Psychology; interesterification; linoleic acid; palm kernel oil; palm olein; γ-linolenic acid; Oils and fats industry; palm olein; Palm kernel oil; n-6 fatty acid; Acidolysis; Polyunsaturated fatty acid; Lipids; Interesterification; Vegetable oil; Edible oil; γ-Linolenic acid; Linoleic acid
• ISSN: 1438-7697; 1438-9312
• DOI: 10.1002/ejlt.200501157

Lipozyme RM IM, a 1,3‐regiospecific lipase, was used as a biocatalyst for the incorporation of γ‐linolenic acid (GLA) and linoleic acid (LA) from borage oil into a blend of palm kernel oil and palm olein (50:50, vol/vol). GLA and LA were concentrated as non‐urea‐complex fatty acids (NUCFA) and NUCFA ethyl esters (NUCFAEE) by urea fractionation. Acidolysis and interesterification were conducted in a solvent‐free system with NUCFA and NUCFAEE as acyl donors, respectively. The effects of temperature and substrate mole ratio on incorporation were also studied. Products were analyzed by gas chromatography. NUCFA were a better substrate for GLA incorporation at 45, 55, and 65 °C. The highest incorporation (16.79%) was obtained at 55 °C. NUCFAEE were a better substrate at 75 °C, with 25.06% GLA incorporation compared to 14.09% with NUCFA. Generally, incorporation increased with increasing substrate mole ratio. A structured lipid containing 33% GLA and 9.4% LA was produced with NUCFAEE as acyl donor at 75 °C and a substrate mole ratio of 4.5. Our work showed that the substrate mole ratio was the most important factor affecting incorporation, and the suitability of either substrate as acyl donor was temperature dependent. The enzyme's preference for GLA incorporation over LA was also observed.