Enzymatic incorporation of docosahexaenoic acid into borage oil

Abstract

Lipase-catalyzed acidolysis of acylglycerols of borage (Borago officinalis L.) oil with a docosahexaenoic acid (DHA) concentrate, prepared from algal oil, in organic solvents was studied. Seven lipases were used as biocatalysts for the acidolysis reaction. Novozyme 435 from Candida antarctica, as compared to lipases from Mucor miehei and Pseudomonas sp., showed the highest degree of DHA incorporation into borage oil. Other lipases tested, such as those from Aspergillus niger, C. rugosa, Thermomyces lanuginousus and Achromobacter lunatus, were rather ineffective in the incorporation of DHA into borage oil. Effects of variation of reaction parameters, namely, enzyme load, temperature, time course, and type of solvent, were monitored for C. antarctica as the biocatalyst of choice. Incorporation of DHA increased with increasing amount of enzyme, reaching 27.4% at an enzyme concentration of 150 lipase activity units. As incubation time progressed, DHA incorporation also increased. After a reaction time of 24 h, the contents of total n-6 and n-3 polyunsaturated fatty acids in acylglycerols were 44.0 and 27.6%, respectively. The highest degree of DHA incorporation was achieved when hexane was used as the reaction medium. The positional distribution of DHA in modified borage oil was determined using pancreatic lipase hydrolysis. Results showed that DHA was randomly distributed over the sn-1, sn-2, and sn-3 positions of the triacylglycerol. Thus, preparation of modified borage oil acylglycerols containing both DHA (22:6n-3; 27.4%) and γ-linolenic acid (18:3n-6; 17.0%) was successfully achieved and products so obtained may have beneficial effects beyond simple physical mixtures of the two oils. The final oil had a ratio of n-3 to n-6 of 0.42-0.62 which is nutritionally more suitable than the original unaltered borage oil.

Concentration of Stearidonic Acid in Free Fatty Acid and Fatty Acid Ethyl Ester Forms from Modified Soybean Oil by Winterization

“…Saponification was done to hydrolyze the TAG of high SDA x-3 oil, following a procedure based on the methods described by Torres et al [21] and Senanayeke and Shahidi [22], with some modifications. According to this methodology, 150 g of the high SDA x-3 oil were mixed with 480 mL of a solution of KOH 3.7 N in ethanol:water (50:50, v/v) with 0.15% w/v of EDTA, in a 1-L cylindrical vessel.…”

Enzymatic and chemical synthesis of phosphatidylcholine regioisomers containing eicosapentaenoic acid or docosahexaenoic acid

“…However, many of the lipases discriminate against polyunsaturated fatty acids [9][10][11], and DHA is usually the fatty acid that is discriminated most. EPA has successfully been incorporated into phospholipids using Rhizomucor miehei lipase (Lipozyme) as catalyst at temperatures of 40-65 7C [12,13], while on the other hand, incorporation of DHA at the sn-1 position of phosphatidylcholine (PC) has been found to be low [14] unless the temperature is elevated to 60 7C [13], with the drawback of considerable acyl migration.…”

Marine Oils and other Marine Nutraceuticals

“…In addition, we produced 91% ␥ -linolenic acid (GLA, 18:3 n-6) concentrate from borage oil [13], which was subsequently used in acidolysis of menhaden and seal blubber oils [14]. Such structured lipids that include GLA, EPA, and DHA were also prepared using borage and evening primrose as a source of GLA and acidolysis with EPA and/or DHA [15,16]. The products so obtained, while similar to those produced by incorporation of GLA into marine oils, differ in the composition and distribution of fatty acids involved.…”