Enzymatic fractionation of fatty acids: Enrichment of γ‐linolenic acid and docosahexaenoic acid by selective esterification catalyzed by lipases

Abstract

Immobilized lipase preparations from seedlings of rape {Brassica napus L.} and Mucor miehei (Lipozyme} used as biocatalysts in esterification and hydrolysis reactions discriminate strongly against y-linolenic and docosahexaenoic acids/acyl moieties. Utilizing this property, y-linolenic acid contained in fatty acids of evening primrose oil has been enriched seven to nine-fold, from 9.5 to almost 85% by selective esterification of the other fatty acids with butanol. Similarly, docosahexaenoic acid of cod fiver oil has been enriched four to five-fold, from 9.4 to 45% by selective esterification of fatty acids tother than docosahexaenoic acid) with butanol. As long as the reaction is stopped before reaching equilibrium, very little of either y-linolenic acid or docosahexaenoic acid are converted to butyl esters, which results in high yields of these acids in the unesterified fatty acid fraction.

Specificity of <i>Mucor miehei</i> lipase on methyl ester substrates

“…The observed differences in the hydrolysis coefficients indicate that the Mucor miehei lipase discriminates against fatty acids/acyl moieties having one, two of three double bonds. These findings are in agreement with the findings of the other workers (Hills et al, 1990). They reported that lipase preparations from seedling of rape and Mucormiehei in non-aqueous media discriminate against 18:1, 18:2 and 18:3 fatty acids.…”

Enrichment of ?-linolenic acid from fungal oil by lipase-catalysed reactions

“…Work from this laboratory has shown recently that ~,-linolenic acid can be efficiently enriched by lipase-catalysed selective esterification with n-butanol of the fatty acids from evening primrose oil with the exception of y-linolenic acid, which is thus obtained as a concentrate in the unesterified fatty acid fraction (Hills et al 1989(Hills et al , 1990b. Selective hydrolysis of the triacylglycerols of evening primrose oil catalysed by lipases also led to enrichment of 7/-linolenoyl moieties in the unhydrolysed acylglycerols (Hills et al 1989).…”

Effect of Phospholipids Transesterified Enzymatically with Polyunsaturated Fatty Acids on Gelatinization and Retrogradation of Starch.

“…The DHA and EPA contents in the PUFAs concentrate were approximately 2 6.1 and 37.9%, respectively. The fraction rich in EPA and DHA prepared by the urea-complex method has been re ported to serve as a good substrate for transesterifica tion (17). Table 2 shows the fatty acid compositions of purified PLs per se and PLs transesterified by the use of immobilized lipase.…”