Browsing by Subject "Lipases"
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- PublicationOpen AccessA simplified kinetic model to describe the solvent-free enzymatic synthesis of wax esters(2021-04-17) Serrano-Arnaldos, M.; Murcia, M.D.; Ortega Requena, Salvadora; Montiel, M.C.; Máximo, F.; Gómez, E.; Bastida, J.; Ingeniería QuímicaBACKGROUND: The use of biotechnological processes at industrial scale is a promising tool to replace conventional synthesis as an efficient and eco-friendly technology. For that purpose, the kinetic modelling of an in-lab optimized enzymatic process prior to scaling-up is of great utility. RESULTS: In this work, a kinetic model for the solvent-free synthesis of cetyl laurate, myristate, palmitate and stearate using different commercial immobilized lipases has been developed. In order to describe the esterification process of the cetyl esters separately and as a mixture similar to natural spermaceti, a pseudo-first-order kinetic has been proposed and tested. A relation between the inverse values of the kinetic constant and the amount of biocatalyst has been observed. The effect of temperature on the reaction rate can be accurately described by the Arrhenius equation except for immobilized Thermomyces lanuginosus, which appears to be less resistant to temperatures above 70 °C. CONCLUSION: Low deviations between experimental and predicted values (R2 ≥ 0.99) indicate that this pseudo-first-order kinetic model can be considered valid for the data range studied. In addition, the reaction rate of spermaceti can be successfully predicted through a weighted average of the kinetic constants obtained during the synthesis of each cetyl ester. This simple but accurate kinetic model for describing the solvent-free enzymatic biosynthesis of wax esters from spermaceti may contribute to extending the application of lipases as industrial catalysts.
- PublicationOpen AccessBiocatalytic synthesis of polymeric esters used as emulsifiers(Croatian Society of Chemical Engineers, 2019) Ortega Requena, Salvadora; Serrano-Arnaldos, M.; Montiel Morte, María Claudia; Máximo, María Fuensanta; Bastida Rodríguez, Josefa; Murcia Almagro, María Dolores; Ingeniería QuímicaPolyglycerol polyricinoleate (PGPR) is a polymeric ester widely used as emulsifier in the food industry. In this work, PGPR biocatalytic synthesis was carried out in a onestep solvent-free enzymatic process using lipase CALB immobilized in Lewatit® Monoplus MP 64 by adsorption. The optimal immobilization conditions were determined: initial enzyme concentration of 13 mg of Lowry protein per mL phosphate buffer pH 7, and ricinoleic acid as a support activator. An immobilized derivative with 35.93 ± 4.90 mg of Lowry protein per g of dry support was obtained. It was used as a catalyst for PGPR production in open air and vacuum batch reactors, and the results obtained showed that only when the reaction equilibrium was shifted towards ester production by means of water removal, the PGPR produced fulfilled the European legislation (acid value ≤ 6 mg of KOH per g of product).
- PublicationOpen AccessChemo-enzymatic production of omega-3 monoacylglycerides using sponge-like ionic liquids and supercritical carbon dioxide(2020-07-22) Alvarez, Elena; Donaire González, Antonio; Garcia-Verdugo, Eduardo; Luis, Santiago V; Lozano Rodríguez, Pedro; Nieto Cerón, Susana; Villa Aroca, Rocío; Bioquímica y Biología Molecular B e InmunologíaA clean chemo-enzymatic synthesis of omega-3 monoacylglycerides was carried out by two consecutive catalytic steps, the enzymatic transesterification of raw fish or linseed oil with solketal for producing fatty acid solketyl esters, followed by the hydrolysis of these solketal moieties catalysed by solid acids (e.g. zeolites) in either supercritical carbon dioxide (scCO2) or sponge-like ionic liquids (SLILs). By using scCO2 as reaction/extraction medium, an excellent performance of both coupled catalytic steps was observed when t-butanol was used as a co-solvent, resulting in a 100% monoacylglyceride yield for seven days under continuous operation and without any loss in catalytic activity. For discontunuous operation, the process involved two separated steps in SLIL and water, respectively, leading to 100% product yield and IL-free monoacylglyceride product by following a cooling and centrifugation protocol, which allow for the full recovery of the enzyme / SLIL / zeolite components of the reaction system that could be reused for at least 6 cycles with unchanged catalytic performance.
- PublicationOpen AccessModification of oligo-Ricinoleic Acid and its derivatives with 10-undecenoic acid via lipase-catalyzed esterification(MDPI, 2012-04-17) Hayes, Douglas G.; Mannam, Vinay K.; Ye, Ran; Zhao, Haizhen; Ortega Requena, Salvadora; Montiel Morte, María Claudia; Ingeniería Química; Facultad de QuímicaLipases were employed under solvent-free conditions to conjugate oligo-ricinoleic acid derivatives with 10-undecenoic acid, to incorporate a reactive terminal double bond into the resultant product. First, undecenoic acid was covalently attached to oligo-ricinoleic acid using immobilized Candida antarctica lipase (CAL) at a 30% yield. Thirty percent conversion also occurred for CAL-catalyzed esterification between undecenoic acid and biocatalytically-prepared polyglycerol polyricinoleate (PGPR), with attachment of undecenoic acid occurring primarily at free hydroxyls of the polyglycerol moiety. The synthesis of oligo-ricinoleyl-, undecenoyl- structured triacylglycerols comprised two steps. The first step, the 1,3-selective lipase-catalyzed interesterification of castor oil with undecenoic acid, occurred successfully. The second step, the CAL-catalyzed reaction between ricinoleyl-, undecenoyl structured TAG and ricinoleic acid, yielded approximately 10% of the desired structured triacylglycerols (TAG); however, a significant portion of the ricinoleic acid underwent self-polymerization as a side-reaction. The employment of gel permeation chromatography, normal phase HPLC, NMR, and acid value measurements was effective for characterizing the reaction pathways and products that formed.
- PublicationRestrictedPreliminary economic assessment: a valuable tool to establish biocatalytic process feasibility with an in-lab immobilized lipase(Wiley, Society of Chemical Industry, 2018-07-27) Serrano-Arnaldos, Mar; Ortega Requena, Salvadora; Montiel Morte, María Claudia; Máximo, María Fuensanta; Bastida Rodríguez, Josefa; Murcia Almagro, María Dolores; Ingeniería Química; Facultad de QuímicaBACKGROUND: Despite the interest that commercial lipases arouse, the number of industrial applications is still very limited. Only high added value products such as cosmetic ingredients that can simultaneously benefit from ‘green chemistry’ and ‘natural’ labels of using biocatalysts can justify the final cost. In any case, process feasibility economic assessment in the first project stages must be done to take decisions about its industrial applicability. RESULTS: This work presents an economic study of the cetyl esters mixture production process similar to natural spermaceti catalyzed by different in-lab immobilized lipase derivatives to determine if they can compete, not only in catalytic properties (activity and stability) but also in price, with the commercial ones. Results highlight that CALB lipase immobilized in Amberlite™ XAD™ 1180 whose direct total cost (1.20 € g−1) is comparable with commercial lipases, is also effective in spermaceti biocatalytic synthesis achieving, under optimal conditions, 98% conversion in less than one hour. CONCLUSION: High conversion values and it reusability (at least 15 times), provides a product with a price (58 € kg−1) similar to that of the well-known Novozym® 435 (56.5 € kg−1). Future scale-up will allow better study the process and gives a more realistic product final price. © 2018 Society of Chemical Industry