Browsing by Author "Ferreira-Dias, Suzana"
Now showing 1 - 8 of 8
Results Per Page
Sort Options
- Argan oil as a rich source of linoleic fatty acid for dietetic structured lipids productionPublication . Simões, Tiago; Ferreira, Jessica; Lemos, Marco F.L.; Augusto, Ana; Félix, Rafael; Silva, Susana F.J.; Ferreira-Dias, Suzana; Tecelão, CarlaArgan oil is rich in long-chain unsaturated fatty acids (FA), mostly oleic and linoleic, and natural antioxidants. This study addresses the production of low-calorie structured lipids by acidolysis reaction, in a solvent-free system, between caprylic (C8:0; system I) or capric (C10:0; system II) acids and argan oil, used as triacylglycerol (TAG) source. Three commercial immobilized lipases were tested: Novozym® 435, Lipozyme® TL IM, and Lipozyme® RM IM. Higher incorporation degree (ID) was achieved when C10:0 was used as acyl donor, for all the lipases tested. Lipozyme® RM IM yielded the highest ID for both systems (28.9 +- 0.05 mol.% C10:0, and 11.4 +- 2.2 mol.% C8:0), being the only catalyst able to incorporate C8:0 under the reaction conditions for biocatalyst screening (molar ratio 2:1 FA/TAG and 55ºC). The optimal conditions for Lipozyme® RM IM in system II were found by response surface methodology (66ºC; molar ratio FA/TAG of 4:1), enabling to reach an ID of 40.9 mol.% of C10:0. Operational stability of Lipozyme® RM IM in system II was also evaluated under optimal conditions, after eight consecutive 24 h-batches, with biocatalyst rehydration between cycles. The biocatalyst presented a half-life time of 103 h.
- Enrichment of sunflower oil with ultrasound-assisted extracted bioactive compounds from Crithmum maritimum L.Publication . Sousa, Gabriela; Alves, Mariana I.; Neves, Marta; Tecelão, Carla; Ferreira-Dias, SuzanaCrithmum maritimum L., or sea fennel, is an edible halophyte plant, rich in phenolic compounds with antioxidant and antimicrobial activities, that naturally grows in Mediterranean coasts. This study aims to incorporate bioactive compounds extracted from lyophilized Crithmum maritimum to sunflower oil assisted by ultrasounds (UAE), to improve its biological value and oxidative stability. UAE conditions were optimized as a function of time (5–20 min) and lyophilized plant concentration (5–20% m/v). The experiments were dictated by a central composite rotatable matrix. Oxidation products were not influenced by UAE conditions. Acidity, chlorophyll, and carotenoid contents were affected by both factors, while total phenols, flavonoids, and antioxidant activity (FRAP method) only increased with plant concentration. Response surfaces were fitted to these experimental results. Flavonoids were highly related with oil antioxidant activity. No sensory defects were detected in supplemented oil (12.5% m/v plant/5 min UAE). The oxidative stability of this oil was evaluated at 60 °C/12 days. Chlorophylls, phenols, radical scavenging (DPPH), and antioxidant activities decreased over time but were always higher than the values in nonsupplemented oil (8.6 and 7‐fold with FRAP and DPPH, respectively). C. maritimum presented high amounts of bioactive compounds with antioxidant activity, adequate for sunflower oil supplementation by UAE.
- Enzymatic modification of grapeseed (Vitis vinifera L.) oil aiming to obtain dietary triacylglycerols in a batch reactorPublication . Bassan, Natalia; Rodrigues, Rafael Hatanaka; Monti, Rubens; Tecelão, Carla; Ferreira-Dias, Suzana; Paula, Ariela V.Structured lipids (SL) are chemically or enzymatically modified oils and fats with respect to their original fatty acid composition or position in acylglycerols. These compounds present improved functional or nutraceutical properties. The present work aimed at the enzymatic synthesis of SL, MLM-type dietary triacylglycerols, that is, those with medium chain fatty acids (M) at the sn-1 and sn-3 positions, and long chain fatty acids (L), in the internal position of the triacylglycerol. Grapeseed oil was selected based on its composition rich in unsaturated fatty acids, principally linoleic acid. This oil was submitted to batch acidolysis with medium chain fatty acids (caprylic or capric) in solvent-free media. Reactions were catalyzed by different immobilized commercial lipases, namely: Lipozyme TL IM® (Thermomyces lanuginosa lipase), Lipozyme RM IM® (Rhizomucor miehei lipase) and Novozym 435® (Candida antarctica lipase B). The incorporation degree (ID) ranged from 23.62 ± 1.34 to 34.53 ± 0.05 mol%, after 24 h reaction at 45 °C, using a molar ratio (MR) fatty acid:oil of 2:1. The best results were obtained using capric acid and Lipozyme RM IM® lipase (34.53 ± 0.05 mol%). In the experimental design, the influence of MR and temperature on ID were evaluated. ID increased with MR and T and was fitted to a saddle-like surface.
- Immobilized heterologous Rhizopus oryzae lipase: A feasible biocatalyst for the production of human milk fat substitutesPublication . Tecelão, Carla; Guillén, Marina; Valero, Francisco; Ferreira-Dias, SuzanaThis work aims at evaluating the potentialities of a heterologous Rhizopus oryzae lipase (rROL) as a feasible biocatalyst, to be used as an alternative to commercial lipases, for the synthesis of Human Milk Fat Substitutes (HMFS). This enzyme was immobilized in three different supports (Accurel® MP 1000, Eupergit® C and Lewatit® VP OC 1600) and tested as catalysts for the acidolysis between tripalmitin and oleic acid, batchwise, at 60 ◦C, in solvent-free medium. The highest molar incorporations of oleic acid in the triacylglycerols were achieved with rROL in Lewatit® VP OC 1600 and Accurel® MP 1000, although the highest immobilization yields were observed with Eupergit® C. Quasi-equilibrium was attained after 6 h or 12 h reaction, with about 30 mol.% and 22 mol.% of oleic acid incorporation, when rROL immobilized in Lewatit and Accurel were used, respectively. Also, 23 h batch operational stability tests were performed: half-life times (t1/2) of 34.5 h and 64.0 h were achieved for rROL immobilized in Accurel® MP 1000 and in Lewatit® VP OC 1600, respectively. An important increase in the operational stability was observed for rROL immobilized in Lewatit after rehydration at the end of each batch (t1/2 = 202 h). Thus, the loss of activity may be explained by a progressive dehydration occurring along the reaction.
- Optimization of ultrasound-assisted extraction of bioactive compounds from Pelvetia canaliculata to sunflower oilPublication . Sousa, Gabriela; Trifunovska, Marija; Antunes, Madalena; Miranda, Isabel; Moldão-Martins, Margarida; Alves, Vitor D.; Vidrih, Rajko; Lopes, Paula Allen; Aparicio, Luis; Neves, Marta; Tecelão, Carla; Ferreira-Dias, SuzanaIn this study, Pelvetia canaliculata L. macroalga, collected from the Atlantic Portuguese coast, was used as a source of bioactive compounds, mostly antioxidants, to incorporate them in sunflower oil with the aim of increasing its biological value and oxidative stability. The lyophilized alga was added to the oil, and ultrasound‐assisted extraction (UAE) was performed. Algae concentration and UAE time varied following a central composite rotatable design (CCRD) to optimize extraction conditions. The following parameters were analyzed in the oils: oxidation products, acidity, color, chlorophyll pigments, carotenoids, flavonoids, total phenolic content, antioxidant activity by DPPH (2,2‐diphenyl‐1‐picrylhydrazyl) and FRAP (ferric reducing antioxidant power) assays, and sensory analysis. Extraction conditions did not affect the acidity and the amount of oxidation products in the oil. Chlorophylls and carotenoid contents increased with algae concentration, while flavonoid extraction did not depend on algae content or UAE time. Total phenolics in the oil were highly related only to FRAP antioxidant activity. Storage experiments of supplemented oil (12.5% algae; 20 min UAE) were carried out under accelerated oxidation conditions at 60 °C/12 days. Antioxidant activity (FRAP) of supplemented oil was 6‐fold higher than the value of non‐supplemented oil. Final samples retained 40% of their initial antioxidant activity. The presence of algae extracts contributed to the increased oxidative stability of sunflower oil.
- Potential of Marine Biomolecules: Advances in Extraction and Applications of Proteins, Polysaccharides, and Antioxidant CompoundsPublication . Sousa, Gabriela; Ferreira-Dias, Suzana; Tecelão, Carla; Alves, Vítor D.Oceans are increasingly viewed as a new frontier for economic development, contributing to the bridge between food industry, sea bioeconomy, and health. Nowadays, oceans are under attention as a strategy for creating opportunities and driving innovation, and their vital importance will become even more evident in the years to come. Therefore, it is crucial to study oceans under a holistic approach, taking the maximum value of their abundant resources in a sustainable way. As such, blue bioeconomy is the path forward, since it is a development strategy that meets the economic potential without compromising the environmental health. A special look needs to be taken at the underutilized resources and by-products, which hold unexploited value. For instance, green macroalgae are widespread marine macroalgae that lack industry applications, despite being rich in biopolymers (polysaccharides) and antioxidants. Moreover, fish by-products are also rich sources of biopolymers, mostly proteins. Thus, among other potential uses, raw materials could be explored to produce functional edible coatings under a blue bioeconomy approach. A detailed characterization of raw materials is the first step for the development of value-added products. These topics will be addressed in this review.
- Production of human milk fat substitutes by interesterification of tripalmitin with ethyl oleate catalyzed by candida parapsilosis lipase/acyltransferasePublication . Tecelão, Carla; Perrier, Véronique; Dubreucq, Eric; Ferreira-Dias, SuzanaIn human milk fat, the saturated fatty acids,namely palmitic acid, are located at the sn-2 position of triacylglycerols (TAG) while unsaturated fatty acids (e.g. oleic acid) are esterified at position sn-1,3. Thus, sn- 1,3-dioleoyl-2-palmitoylglycerol (OPO) is the target TAG to be used as human milk fat substitutes (HMFS) in infant formulas. In this study, the noncommercial recombinant lipase/acyltransferase from Candida parapsilosis (CpLIP2) was immobilized in Accurel MP1000, and used as a biocatalyst for the interesterification of tripalmitin with ethyl oleate in a solvent-free medium, to obtain structured lipids used as HMFS. Different molar ratios (MR) of ethyl oleate to tripalmitin (2:1–8:1) were used. After 4 h reaction at 60ºC, about 30 mol% of oleic acid incorporation was already observed for all tested MR. An apparent equilibrium was reached after 8–24 h, with 32–51 mol% final incorporation, increasing with the MR. The incorporation of oleic acid into TAG was compared with the maximum predicted values when a random or a sn-1,3-regioselective biocatalyst was used. The obtained values are consistent with the maximum incorporation expected for a sn-1,-3-regioselective enzyme. In fact, the amount of oleic acid at position sn-2 was approximately 15% for all the MR tested, which is explained by the acyl migration phenomenon. CpLIP2 exhibited higher activity than most commercial immobilized lipases (e.g. faster reaction in solvent-free media, low enzyme load, and low MR needed), and showed a recognized sn-1,3 regioselective behavior.
- Production of human milk fat substitutes enriched in omega-3 polyunsaturated fatty acids using immobilized commercial lipases and Candida parapsilosis lipase/acyltransferasePublication . Tecelão, Carla; Silva, Joana; Dubreucq, Eric; Ribeiro, Maria H.; Ferreira-Dias, SuzanaIn human milk fat (HMF), palmitic acid (20-30%), the major saturated fatty acid, is mostly esterified at the sn-2 position of triacylglycerols, while unsaturated fatty acids are at the sn-1,3 positions, conversely to that occurring in vegetable oils. This study aims at the production of HMF substitutes by enzyme-catalyzed interesterification of tripalmitin with (i) oleic acid (system I) or (ii) omega-3 polyunsaturated fatty acids (omega-3 PUFA) (system II) in solvent-free media. Interesterification activity and batch operational stability of commercial immobilized lipases from Rhizomucor miehei (Lipozyme RM IM), Thermomyces lanuginosa (Lipozyme TL IM) and Candida antarctica (Novozym 435) from Novozymes, DK, and Candida parapsilosis lipase/acyltransferase immobilized on Accurel MP 1000 were evaluated. After 24-h reaction at 60 °C, molar incorporation of oleic acid was about 27% for all the commercial lipases tested and 9% with C. parapsilosis enzyme. Concerning omega-3 PUFA, the highest incorporations were observed with Novozym 435 (21.6%) and Lipozyme RM IM (20%), in contrast with C. parapsilosis enzyme (8.5%) and Lipozyme TL IM (8.2%). In system I, Lipozyme RM IM maintained its activity for 10 repeated 23-h batches while for Lipozyme TL IM, Novozym 435 and C. parapsilosis enzyme, linear (half-life time, t1/2 = 154 h), series-type (t1/2 = 253 h) and first-order (t1/2 = 34.5 h) deactivations were respectively observed. In system II, Lipozyme RM IM showed linear deactivation (t1/2 = 276 h), while Novozym 435 (t1/2 = 322 h) and C. parapsilosis enzyme (t1/2 = 127 h), presented series-type deactivation. Both activity and stability of the biocatalysts depended on the acyl donor used.