Synthesis of structured triacylglycerols enriched in n-3 fatty acids by immobilized microbial lipase

Abstract

The search for new biocatalysts has aroused great interest due to the variety of micro-organisms and their role as enzyme producers. Native lipases from Aspergillus niger and Rhizopus javanicus were used to enrich the n-3 long-chain polyunsaturated fatty acids content in the triacylglycerols of soybean oil by acidolysis with free fatty acids from sardine oil in solvent-free media. For the immobilization process, the best lipase/support ratios were 1:3 (w/w) for Aspergillus niger lipase and 1:5 (w/w) for Rhizopus javanicus lipase using Amberlite MB-1. Both lipases maintained constant activity for 6 months at 4 °C. Reaction time, sardine-free fatty acids:soybean oil mole ratio and initial water content of the lipase were investigated to determine their effects on n-3 long-chain polyunsaturated fatty acids incorporation into soybean oil. Structured triacylglycerols with 11.7 and 7.2% of eicosapentaenoic acid + docosahexaenoic acid were obtained using Aspergillus niger lipase and Rhizopus javanicus lipase, decreasing the n-6/n-3 fatty acids ratio of soybean oil (11:1 to 3.5:1 and 4.7:1, respectively). The best reaction conditions were: initial water content of lipase of 0.86% (w/w), sardine-free faty acids:soybean oil mole ratio of 3:1 and reaction time of 36 h, at 40 °C. The significant factors for the acidolysis reaction were the sardine-free fatty acids:soybean oil mole ratio and reaction time. The characterization of structured triacylglycerols was obtained using easy ambient sonic-spray ionization mass spectrometry. The enzymatic reaction led to the formation of many structured triacylglycerols containing eicosapentaenoic acid, docosahexaenoic acid or both polyunsaturated fatty acids.

Lipase-Catalyzed Synthesis of Structured Fatty Acids Enriched with Medium and Long-Chain n-3 Fatty Acids via Solvent-Free Transesterification of Skipjack Tuna Eyeball Oil and Commercial Butterfat

“…ASL-L could add 1.96% linoleic acid (C18:2), 0.70% linolenic acid (C18:3), 6.38% EPA (C20:5), and 17.9% DHA (C22:6) at a CBF/STEO ratio of 3:1 (Table 3). Similar results were observed when immobilized lipases from Aspergillus niger and Rhizopus javanicus and Lipozyme 435 were applied for the incorporation of n-3 fatty acids in the soybean oil and both lipases showed maximum n-3 fatty acid incorporation at 3:1 (acyl donor:acyl acceptor) ratio [39,40].…”

“…Additionally, among the MUFAs present in the substrate mixture, ASL-L incorporated 0.81% myristoleic acid (C14:1), 3.34% palmitoleic acid (C16:1), 0.84% heptadecanoic acid (C17:1), 0.86% elaidic acid (C18:1), and 15.3% oleic acid (C18:1) to M-STEO (Table 3). Similar effects of enzyme concentration were reported when Lipozyme RM and Lipozyme TL were used for the interesterification of coconut oil and catfish oil to produce modified lipids containing both MCFAs and PUFAs at their glycerol backbones [39].…”

Microbial lipases and their industrial applications: a comprehensive review

“…The loss of catalytic activity of Lipozyme IM in soybean oil reduced the rate of change in oleoyl and linoleoyl moiety arrangements in soybean oil decreased. The lipase catalyzed acidolysis of soybean oil with oleic acid to increase oleic acid content in an organic solvent [ 256 , 257 ]. The degumming step can be conceded out with a phospholipase in the physical refining of vegetable oils.…”

Enzymatic Synthesis of Human Milk Fat Substitute - A Review on Technological Approaches

“…Lipase (triacylglycerol acyl-hydrolase, EC 3.1.1.3) is commonly used for oil or fat hydrolysis. In non-aqueous media, lipase can also catalyze the esterification, acidolysis, alcoholysis and interesterification ( 20 , 27 - 29 ). The lipase-catalyzed interesterification involves the reversible reaction of simultaneous hydrolysis and esterification reactions ( 30 ).…”