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.

Effect of a commercial pectinmethylesterase on tomato paste consistency

Background: Consistency is one of the main traits that define commercial quality and price of tomato paste. Pectins are partially responsible for consistency in tomato paste, therefore enzymatic pectin modification could be used to increase paste consistency. Results: This work reports the effects of a commercial enzymatic preparation of pectin-methyl-esterase (PME) (NovoShape™) on tomato paste consistency taking into account variables as enzyme/substrate ratio (0,1 percent w/w - 1 percent w/w), reaction time (0 hr - 3 hrs) and reaction temperature (40ºC-60ºC). The results indicate that NovoShape™ increased consistency when reaction temperature ranged from 40 to 50ºC with an enzyme/substrate ratio of 0.5 to 1 (l PME solution/g tomato paste on dry base). On the other hand, enzymatic treatment was not effective at 60ºC with an enzyme/substrate ratio of 0.1 percent. Conclusions: Based on these results, addition of NovoShape™ is a good technological approach to increase tomato paste consistency.