Increase in the γ‐linolenic acid content by solvent winterization of fungal oil extracted fromMortierella genus

Abstract

The fungal oil extracted from Mortierella ramanniana var. angulispora (IFO 8187) was solvent winterized in order to raise the content of 7-1inolenic acid (GLA). Effects of winterization conditions (solvent, oil concentration in the solvent and temperature) and changes of glyceride compositions were discussed. The fungal oil was separated into four diglycerides and 17 triglycerides (TG) with high performance liquid chromatography. The predominant species were POO, POP and LOP, whose contents were 24.4, 22.9 and 9.4% of the total TG, respectively. Ethanol at 4~ gave the highest GLA content of 10.5% in spite of lower yield than with acetone at -20~The highest separation efficiency for GLA (~GLA) was 0.27 with acetone at -20~ and 10% oil concentration, resulting in 8.3% of GLA from the fungal oil at 5.7% GLA. In case of lower oil concentration at 5-20%, ~GLA showed higher in the following order: acetone (-20~ ~ nhexane (-20~ ~ acetone (4~ ~ petroleum ether (-20~The winterization process also proved to be effective for the separation of TG type, Sa2U (Sa; saturated fatty acid; U, unsaturated fatty acid) into the crystallized fraction and SaU 2 into the liquid fraction. Acetone at -20~ showed higher separation efficiency for triunsaturated TG than the other solvents.

Borage and evening primrose oil

“…Chemical methods reported for enriching GLA include solvent winterization [18], urea fractionation [19], a combination of urea fractionation and silica gel chromatography [20], and the use of Y-Zeolite to concentrate GLA ethyl esters [21]. Using a low-temperature solvent crystallization process followed by lipase-catalyzed esterification, Ju and Jen [22] obtained very pure GLA from BO fatty acids.…”

Fractionation of menhaden oil and partially hydrogenated menhaden oil: Characterization of triacylglycerol fractions

“…After crystallization is complete, the solid phase is separated from the liquid phase by one of several physical processes (4,5). Alternatively, solvent (typically acetone) crystallization is used for promoting TAG crystal formation, because TAG at low temperature generally form more stable crystals with solvent than without solvent (6). Accordingly, TAG species with a higher (or lower) level of desirable (or undesirable) fatty acids can be separated by both fractional crystallization processes for use in nutritional or functional food applications.…”

Preparative and Industrial‐Scale Isolation and Purification of Omega‐3 Polyunsaturated Fatty Acids from Marine Sources

“…Crystallization of SFA from a solution of fatty acid mixture in organic solvents, especially a polar type, is a promising way of separation. It has been reported that use of different organic solvents and temperatures affects the concentration of PUFA [22]. With proper choice of solvent and temperature, PUFA can be concentrated into a non-crystallized fraction.…”