title: 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 36h, 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.
authors.affiliation: Universidade São Francisco, Laboratory of Multidisciplinary Research, Bragança Paulista, SP, Brazil. Electronic address: melisa.bio@gmail.com.
authors.forename: Maria Elisa Melo Branco de
authors.initials: ME
authors.lastname: Araújo
authors.affiliation: Universidade São Francisco, Laboratory of Multidisciplinary Research, Bragança Paulista, SP, Brazil.
authors.forename: Paula Renata Bueno
authors.initials: PR
authors.lastname: Campos
authors.affiliation: Universidade São Francisco, Laboratory of Multidisciplinary Research, Bragança Paulista, SP, Brazil.
authors.forename: Thiago Grando
authors.initials: TG
authors.lastname: Alberto
authors.affiliation: Universidade Estadual de Campinas, College of Food Engineering, Campinas, SP, Brazil.
authors.forename: Fabiano Jares
authors.initials: FJ
authors.lastname: Contesini
authors.affiliation: Universidade São Francisco, Laboratory of Multidisciplinary Research, Bragança Paulista, SP, Brazil.
authors.forename: Patrícia de Oliveira
authors.initials: PO
authors.lastname: Carvalho
mesh_terms: D002265:Carboxylic Ester Hydrolases / Q000737:chemistry*; D002849:Chromatography, Gas; D004795:Enzyme Stability; D004800:Enzymes, Immobilized; D015525:Fatty Acids, Omega-3 / Q000138:chemical synthesis; D021241:Spectrometry, Mass, Electrospray Ionization; D014280:Triglycerides / Q000737:chemistry
chemical_list: D004800:Enzymes, Immobilized; D015525:Fatty Acids, Omega-3; D014280:Triglycerides; D002265:Carboxylic Ester Hydrolases
keywords: Immobilization; Lipase; Polyunsaturated fatty acids; Soybean oil