Production Of Ethyl Esters Research Articles

Catalyst-free production of fatty acid ethyl esters (FAEE) from macauba pulp oil

In this study, the production of fatty acid ethyl esters (FAEE) from macauba pulp oil and pressurized ethanol was investigated. The experiments were conducted without the addition of catalyst, at 20 MPa, to determine the effect of temperature (200 to 300 °C) and the oil to ethanol mass ratio (1:1 and 1:2) on the FAEE content and different residence times (10 to 45 min). The effect of the addition of n-hexane to the oil (20 wt%) as a co-solvent was also evaluated. The use of high temperatures (275 and 300 °C) resulted in high FAEE content (∼90%). Increasing the amount of ethanol in the reaction medium contributed to the formation of esters only at operating temperatures of 200 to 250 °C. It was also observed that with the addition of co-solvent (in the oil) it was possible to obtain high amounts of FAEE in a shorter reaction time. In addition, a low content of unreacted compounds (∼8.0%) and the conversion of ∼90 and 99% of the free fatty acids and triglycerides were observed, respectively.

Continuous Ultrasound-Assisted Esterification and Transesterification of Palm Fatty Acid Distillate for Ethyl Ester Production

Ethyl ester production from palm fatty acid distillate (PFAD) with ethanol in the presence of sulfuric acid and potassium hydroxide was performed in a continuous three-step process using the ultrasound clamps and an ultrasonic probe. The ultimate goal was to produce biodiesel from the PFAD. In the first and second esterification steps, 16 units of a 400 W ultrasound clamp (20 kHz) were attached 100-m apart along each tubular reactor. In the third transesterification step, a 1000-W ultrasonic homogenizer (18 kHz) was used in a 100-mL continuous reactor. A composite central design of experiments and the response surface methodology (RSM) were used to develop predictive models and identify the optimal conditions of each step based on the purities of ethyl ester. The optimal conditions in the first step were 46.1 vol.% ethanol, 1.4 vol.% sulfuric acid, and purity 66.68 wt.% ethyl ester. In the second step, the optimized conditions were 57 vol.% ethanol, and 2.1 vol.% sulfuric acid, purity 95.32 wt.% ethyl ester. The final transesterification step was carried out with 14.6 vol.% ethanol and 3.9 gKOH L−1. As a result, a final ethyl ester purity of 98.15 wt.% was achieved in the biodiesel using the three-step process.

Effect of Unsaturated Fatty Acids on Intra-Metabolites and Aroma Compounds of Saccharomyces cerevisiae in Wine Fermentation.

The small changes in concentration of unsaturated fatty acids (UFAs) cause a significant influence on the aromatic component of wines. In this work, the effect of UFAs mixture (including linoleic, oleic, and α-linolenic acids) addition on intra-metabolites and aromatic compounds of two Saccharomyces cerevisiae strain EC1118 and BDX were investigated in red wine fermentation, respectively. The results showed that the pre-fermentative addition of UFAs significantly modified the physiological and energetic state of cells, and affected the levels of intra-metabolites in glycolysis pathway and TCA cycle, redox balance, ATP pool, fatty acids, and amino acids metabolism, which consequently altered the chemical and volatile composition of the wines. Different with the control wine, the wines produced by UFAs addition were characterized with higher amounts of glycerol, C6-alcohols and higher alcohols, and lower levels of acetic acid, medium-chain fatty acids, and acetate esters. Interestingly, the production of ethyl esters showed opposite profiles in different strains due to the distinct expression of EEB1, indicating that the effect of UFAs on ethyl esters syntheses is strain-specificity. Our results highlighted the effectiveness of modulating UFAs content in shaping aroma characteristics, and verified that fine adjusting the content of UFAs combined with inoculating proper yeast is a promising strategy to modulate the aromatic quality of wine, which probably provides an alternative approach to meet the expectations of wine consumers for diverse aromatic qualities.

Sustainable Synthesis of Omega-3 Fatty Acid Ethyl Esters from Monkfish Liver Oil

The search for economic and sustainable sources of polyunsaturated fatty acids (PUFAs) within the framework of the circular economy is encouraged by their proven beneficial effects on health. The extraction of monkfish liver oil (MLO) for the synthesis of omega-3 ethyl esters was performed to evaluate two blending systems and four green solvents in this work. Moreover, the potential solubility of the MLO in green solvents was studied using the predictive simulation software COnductor-like Screening MOdel for Realistic Solvents (COSMO-RS). The production of ethyl esters was performed by one or two-step reactions. Novozym 435, two resting cells (Aspergillus flavus and Rhizopus oryzae) obtained in our laboratory and a mix of them were used as biocatalysts in a solvent-free system. The yields for Novozym 435, R. oryzae and A. flavus in the one-step esterification were 63, 61 and 46%, respectively. The hydrolysis step in the two-step reaction led to 83, 88 and 93% of free fatty acids (FFA) for Novozym 435, R. oryzae and A. flavus, respectively. However, Novozym 435 showed the highest yield in the esterification step (85%), followed by R. oryzae (65%) and A. flavus (41%). Moreover, selectivity of polyunsaturated fatty acids of R. oryzae lipase was evidenced as it slightly esterified docosahexaenoic acid (DHA) in all the esterification reactions tested.

Ionic liquid synergistic effect between preparation of hybrid supports and immobilization of lipase applied to esters production

The present work aims to evaluate the synergistic effect of imidazolium-based ionic liquids (IL) in the preparation and immobilization of Burkholderia cepacia lipase in a new hybrid support of poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) and silica. In addition, these biocatalysts were applied in transesterification reactions of crude coconut oil for the production of ethyl esters. Lipase immobilized on hybrid support with [C4min][NTf2] or [C6min][NTf2] ionic liquid exhibited nearly ≈ 1.6-fold immobilization yield greater than IB-Control. The use of IL during the preparation of the hybrid support promoted changes in its morphological structure as presented by B.E.T. and FTIR. Thermogravimetric analyzes were used to characterize the prepared derivatives and support the results of immobilization yields and the synergic effect of IL used. Transesterification reactions applying biocatalysts showed that the conversion maximum in esters (59%) was found under conditions of molar ratio 1:7 (oil:ethanol) in 72 h of reaction. These results were obtained using [C4min][NTf2] during the preparation of the hybrid support for the immobilization of Burkholderia cepacia lipase, thus showing the potential of these new biocatalysts.

Production of new nanobiocatalysts via immobilization of lipase B from C. antarctica on polyurethane nanosupports for application on food and pharmaceutical industries

Nanobiocatalysts were produced via immobilization of CalB lipase on polyurethane (PU) based nanoparticles and their application on the synthesis of important industrial products was evaluated. Nanoparticles of polyurethane functionalized with poly(ethylene glycol) (PU-PEG) were synthetized through miniemulsion polymerization and the addition of crosslinking agents were evaluated. The nanoparticles were employed as support for CalB and the kinetic parameters were reported. The performance of new biocatalysts was evaluated on the hydrolysis reaction of p-NPB and on the enantioselective hydrolysis of (R,S)-mandelic acid. The esterification reaction was evaluated on the production of ethyl esters of Omega-3. The effect of poly(ethylene glycol) molar mass (400, 4000 or 6000 Da)on the biocatalyst activity was also analyzed. The PU-PEG6000-CalB showed the highest value of the kinetic parameters, highlighting the high reaction rate. The addition of trehalose as crosslinking agent improved the thermal stability of the biocatalysts. PU-PEG400-CalB was the most active nanobiocatalyst, exhibiting a ethyl esters production of 43.72 and 16.83 mM.U -1 using EPA and DHA, respectively. The nanobiocatalyst was also applied in enantiomeric resolution of mandelic acid, showing promising enantiomeric ratios. The results obtained in this work present alternative and sustainable routes for the synthesis of important compounds used on food and pharmaceutical industries.

Catalytic enhancement of calcium oxide from green mussel shell by potassium chloride impregnation for waste cooking oil-based biodiesel production

This work investigates the optimization of fatty acid ethyl ester (FAEE, biodiesel) production from waste cooking oil (WCO) via the transesterification with ethanol (EtOH) under calcium oxide catalyst from green mussel shell impregnated with potassium chloride (KCl). The green mussel shell is calcined at 900 °C for 5 h, grounded into powder prior to immersion into KCl solution, and characterized by an attenuated total reflection Fourier transform infrared (ATR/FT-IR) spectrophotometer and X-ray diffraction (XRD) before using as a catalyst. The catalytic performances are evaluated via WCO-EtOH transesterification and optimized for production parameters. The maximum yield of FAEE is 97% w/w from the following optimum conditions: catalyst ratio of 4.0% w/w, EtOH-to-WCO molar ratio of 10:1 at 80 °C in 3 h. This work benefits on value-added raw materials, such as green mussel shell and WCO, which can be renewed for energy.

Optimization Using Response Surface Methodology (RSM) for Biodiesel Synthesis Catalyzed by Radiation-Induced Kenaf Catalyst in Packed-Bed Reactor

In this study, continuous transesterification of refined palm oil by using radiation-induced kenaf denoted as anion exchange kenaf catalyst in a packed-bed reactor was developed. The application of full factorial design and response surface methodology (RSM) based on the central composite design (CCD) was used to design the process and analyzed the effect of reactor operating variables such as packed bed height, the molar ratio of oil to ethanol and volumetric flow rate on the production of fatty acid ethyl ester (FAEE). The statistical analysis results showed that all three operating parameters affect the reaction efficiency significantly. The optimum conditions were determined to be 9.81 cm packed bed height, a molar ratio at 1:50, and a volumetric flow rate of 0.38 mL min−1. Three tests were carried out to verify the optimum combination of process parameters. The predicted and actual values of molar conversion fatty acid ethyl ester (FAEE) molar conversion were 97.29% and 96.87%, respectively. The reusability of kenaf fiber-based catalysts is discussed with a specially highlighted on fiber dissolution, leaching, and fouling. Nevertheless, the impurities absorption properties of anion exchange kenaf catalyst towards biodiesel production could eventually simplify the biodiesel purification steps and cost. In sum, anion exchange kenaf catalyst shows the potential commercial applications to transesterification of FAEE in a packed-bed reactor.

Lipase From Rhizomucor miehei Immobilized on Magnetic Nanoparticles: Performance in Fatty Acid Ethyl Ester (FAEE) Optimized Production by the Taguchi Method.

In this communication, it was evaluated the production of fatty acid ethyl ester (FAAE) from the free fatty acids of babassu oil catalyzed by lipase from Rhizomucor miehei (RML) immobilized on magnetic nanoparticles (MNP) coated with 3-aminopropyltriethoxysilane (APTES), Fe3O4@APTES-RML or RML-MNP for short. MNPs were prepared by co-precipitation coated with 3-aminopropyltriethoxysilane and used as a support to immobilize RML (immobilization yield: 94.7 ± 1.0%; biocatalyst activity: 341.3 ± 1.2 Up–NPB/g), which were also activated with glutaraldehyde and then used to immobilize RML (immobilization yield: 91.9 ± 0.2%; biocatalyst activity: 199.6 ± 3.5 Up–NPB/g). RML-MNP was characterized by X-Ray Powder Diffraction (XRPD), Fourier Transform-Infrared (FTIR) spectroscopy and Scanning Electron Microscope (SEM), proving the incorporation and immobilization of RML on the APTES matrix. In addition, the immobilized biocatalyst presented at 60°C a half-life 16–19 times greater than that of the soluble lipase in the pH range 5–10. RML and RML-MNP showed higher activity at pH 7; the immobilized enzyme was more active than the free enzyme in the pH range (5–10) analyzed. For the production of fatty acid ethyl ester, under optimal conditions [40°C, 6 h, 1:1 (FFAs/alcohol)] determined by the Taguchi method, it was possible to obtain conversion of 81.7 ± 0.7% using 5% of RML-MNP.

Ethyl esters production catalyzed by immobilized lipases is influenced by n-hexane and ter-amyl alcohol as organic solvents.

Lipase stability in organic solvent is crucial for its application in many biotechnological processes as biocatalyst. One way to improve lipase's activity and stability in unusual reaction medium is its immobilization on inert supports. Here, lipases from different sources and immobilized through weak chemical interactions on hydrophobic and ionic supports had their transesterification ability dramatically dependent on the support and also on the solvent that had been used. The ethanolysis of sardine oil was carried out at the presence of cyclohexane and tert-amyl alcohol, in which Duolite A568-Thermomyces lanuginosa lipase derivative achieved 49% of ethyl esters production after 24h in cyclohexane. The selectivity of immobilized lipases was also studied and, after 3h of synthesis, the reaction with Duolite A568-Thermomyces lanuginosa derivative in cyclohexane produced 24% ethyl ester of eicosapentaenoic acid and 1.2% ethyl ester of docosahexaenoic acid, displaying a selectivity index of 20 times the ethyl ester of eicosapentaenoic acid. Different derivatives of Candida antarctica lipases fraction B (CALB) and phospholipase Lecitase® Ultra (Lecitase) were also investigated. Along these lines, a combination between these factors may be applied to improve the activity and selectivity of immobilized lipases, decreasing the total cost of the process.

In Situ Transesterification of Marine Microalgae Biomass via Heterogeneous Acid Catalysis

Microalgae have been widely considered as a promising alternative to renewable feedstock to biofuel production. Considering the many oleaginous strains of microalgae, this work assessed the potential of two species, Chlorella minutissima and Nannochloropsis gaditana, to be tested as raw material for ethyl esters production of biodiesel value. This work demonstrates an efficient pilot-size photoautotrophic growth of the two strains using 40-L bubble-column photobioreactors, providing lipid productivities of around 15.2 and 8.7 mg L−1 day−1 for C. minutissima and N. gaditana, respectively. The lipid-bearing biomass, which presented fatty acids composition similar to vegetable oils, such as soybean, rich in palmitic, oleic, and linoleic acids, was then assayed in direct trans/esterification reactions using ethanol as acyl donor, lipid extracting and solvent for the liquid phase in a pressurized reactor. The reactions, which were catalyzed by a heterogeneous acid catalyst (12-molybdophosphoric acid supported onto aluminum oxide), demonstrated an efficient route for producing a product mixture containing ester contents greater than 96.5 wt%, total conversion of triacylglycerols, and low levels of mono- and diacylglycerols, promoting an ethyl ester mixture with possible integration within the biodiesel market specifications.

Synthesis of polymer based catalyst: Optimization and kinetics modeling of the transesterification of Pistacia chinensis oil with diethyl carbonate using acidic ionic liquids

A novel solid acidic polymeric ionic liquid catalyst was synthesized for ethyl esters production via the esterification of oleic acid with ethanol, normally transesterification of Pistacia chinensis oil with diethyl carbonate. Gas chromatography-mass spectroscopy analysis was used to characterize the products and optimize the reaction conditions to provide P. chinensis oil derived ethyl esters in 93% yield. Kinetic studies performed at different temperatures revealed that the conversion of P. chinensis oil to an ethyl ester follows first order reaction kinetics. The properties of ethyl esters were determined, found to meet the ASTM D6751-02. Results revealed that the catalyst had perfect utility after several runs without much loss in activity. The mild conditions (1:5) P. chinensis oil:diethyl carbonate molar ratio, 300 wt% PIL loading, 120 °C, 400 rpm, 6 h, recyclability of the catalyst make the proposed synthesis a sustainable method for the development of ecofriendly, cost-effective biofuels.

Synthesis of DHA/EPA Ethyl Esters via Lipase-Catalyzed Acidolysis Using Novozym® 435: A Kinetic Study

DHA/EPA ethyl ester is mainly used in the treatment of arteriosclerosis and hyperlipidemia. In this study, DHA+EPA ethyl ester was synthesized via lipase-catalyzed acidolysis of ethyl acetate (EA) with DHA+EPA concentrate in n-hexane using Novozym® 435. The DHA+EPA concentrate (in free fatty acid form), contained 54.4% DHA and 16.8% EPA, was used as raw material. A central composite design combined with response surface methodology (RSM) was used to evaluate the relationship between substrate concentrations and initial rate of DHA+EPA ethyl ester production. The results indicated that the reaction followed the ordered mechanism and as such, the ordered mechanism model was used to estimate the maximum reaction rate (Vmax) and kinetic constants. The ordered mechanism model was also combined with the batch reaction equation to simulate and predict the conversion of DHA+EPA ethyl ester in lipase-catalyzed acidolysis. The integral equation showed a good predictive relationship between the simulated and experimental results. 88–94% conversion yields were obtained from 100–400 mM DHA+EPA concentrate at a constant enzyme activity of 200 U, substrate ratio of 1:1 (DHA+EPA: EA), and reaction time of 300 min.

Waste oil/crambe oil blends for ethyl ester production under supercritical conditions

The objective of this study was to evaluate the ethyl esters (EE) production obtained with waste oil (WO) and crambe oil (CO) blends using supercritical ethanol. Experiments were carried out to evaluate the effect of temperature, residence time and water concentration (in the ethanol) on the EE yield. Reactions were also conducted with pure oils for comparison purposes. The results show that an increase in temperature and residence time favors the production of esters; however, with an increase in decomposition. The EE yields obtained followed the order CO>blend 25/75 (WO/CO)>blend 50/50 (WO/CO)>WO. It was found that the degree of decomposition is related to the content of polyunsaturated fatty acids. The addition of water to the ethanol promoted an increase in the EE yield in the initial reaction time, but from 30 min the observed effect was minimal. Ethyl linoleate and linolenate underwent degradation under the applied operating conditions. Therefore, the blend with 25/75 (WO/OC) and the addition of 5 wt% of water provided a better yield, with ∼70 % esters at 300 °C and ∼10 wt% unreacted compounds.

The utilization of chicken bones as heterogeneous catalyst (CaO) in the production of fatty acid ethyl ester from crude palm oil by using ethanol as solvent

Fatty acid ethyl ester is one of the most potential alternative energy because it is renewable and environmentally friendly. Fatty acid ethyl ester is usually made by transesterification using heterogeneous alkali catalyst. Chicken bones ash (CaO) is heterogeneous alkali catalyst which is non-corrosive and environmentally friendly. It can also be separated easily from the product by filtration and less removal problem than homogeneous catalyst. This catalyst was made by grinding and calcination the chicken bones. Others variables used in this research were the dosage of the catalyst, molar ratio of ethanol to crude palm oil and reaction temperature. The best yield of the fatty acid ethyl ester was 90.052% at the condition of 17:1 ethanol to crude palm oil molar ratio, 70 °C reaction temperature, 7% of catalyst (w/w), 7 hours of reaction time and 500 rpm stirring speed.

K- and Cu-doped CaTiO3-based nanostructured hollow spheres as alternative catalysts to produce fatty acid ethyl esters as potential biodiesel

New functional polycation oxide-type catalysts were synthesized by the ultrasonic spray-pyrolysis method. The catalytic activity in the production of fatty acid ethyl esters (FAEE’s) using soybean oil was studied. Catalysts are conformed by nanostructured hollow spheres of low density with a stoichiometric formula Ca1-xKxTiCux/2O3. The influence of the substitutional ratio (x) upon the catalytic activity was verified. The Ca1-xKxTiCux/2O3 sample with x = 0.3 showed the highest activity with a yield up to 89 % to produce fatty acid ethyl esters (FAEE’s) after 24 h reaction using 15 wt.% catalysts, 120 °C and 40 bars. The enhancement in the activity was ascribed to the substitution of the Ca+2 sites by K+ and Ti+4 by Cu+2 and to the hollow morphology favoring a more effective interaction between the soybean oil and the active basic sites of the catalysts.

Ethyl ester production from Iranian bitter almond (BAO) oil to improve the performance and emissions of OM457 diesel engine

Biodiesel is among the biofuels. In this study, biodiesel was produced from Iranian bitter almond (BAO) oil through the transesterification process by using ethanol (BAO ethyl ester). BAO can be considered a non-edible oil, so this parameter can add to the benefits of biodiesel production. Biodiesel was prepared in two samples, containing 5 and 20 volumetric percent of biodiesel in diesel fuel respectively (B5 and B20). The tests were done based on the ECE R-85 standard. According to this standard, the engine test is performed at four loads (25%, 50%, 75%, and 100%) and two rotational speeds, 1400 rpm and 2000 rpm. These correspond to the maximum torque and power respectively. Experimental tests were run on engine performance and emissions of biodiesel fuels. The results were studied and all the parameters were compared with diesel fuel. According to the results, the maximum brake power increased (about 9.5% compared with diesel fuel) in B20, at a load of 20% and a rotational speed of 2000 rpm. Also the maximum reduction of BSFC (about 8.6% lower than diesel fuel) happened for B20 at a load of 25% and a rotational speed of 2000 rpm. Although, the brake-specific fuel consumption (BSFC) decreased at a rotational speed of 2000 rpm and all loads for both B5 and B20 compared with diesel. Regarding the effect of biodiesel on engine emissions, the emission of nitrogen oxide (NOx) at all loads for both B5 and B20 was greater than that for diesel fuel. The carbon dioxide (CO2) emission of the engine was lower for B5 at a rotational speed of 2000 rpm and at all loads compared with diesel fuel.

Production of Ethyl Ester With The Influence of Electrode type, Rection Time and Electric Voltage From Used Frying Oil

Ethyl ester or biodiesel that is an alternative energy because of its renewable nature. The production of ethyl ester involves an alcoholysis reaction between ethanol and triglycerides using a strong base catalyst. The source of triglycerides is derived from used frying oil to increase the economic value of used frying oil whose production in indonesia reaches 4 million tons/year. Used frying oil is taken from restaurants in Palembang, South Sumatra. It has free fatty acid values of 1.024% so that transesterification can be carried out directly using a strong KOH base catalyst. The research was conducted using an electrolysis reaction with NaCl as an electrolyte. Variations of made to the type of electrodes, namely aluminum and stainless steel, the reaction time was 3 hours; 3.5 hours; 4 hours; 4.5 hours; and 5 hours and the supplied current voltage which is 15 V; 25 V; 35 V to see the effect on the percent yield of ethyl ester produced. The highest percent yield of Ethyl Ester was obtained samples with a reaction time of 3.5 hours, a voltage of 35 V, and an aluminum electrode of 99.8%.

Two-step sub/supercritical water and ethanol processes for non- catalytic biodiesel production

The catalyst-free two-step process has been developed for biodiesel production using low-grade feedstocks. The first step consists of triglycerides hydrolysis under subcritical water conditions to generate and increase free fatty acid (FFA) content for ethyl ester production. In its subcritical state, water can be used as both a solvent and a reactant for the hydrolysis of triglycerides. The hydrolyzed product mixture is separated by decantation into the oil phase of FFA (upper layer) and a water phase that contains glycerol (lower layer). In the second step, the hydrolyzed products of free fatty acids were successfully esterified to their ethyl ester in supercritical ethanol conditions without any catalyst. Under the sub- and supercritical conditions of water and ethanol, the hydrolysis and the esterification reactions proceed quickly, with a conversion of greater than 98 % after 10−20 min. This two-step process for biodiesel production offers several advantages, such as milder reaction conditions and pollution reduction due to the use of water instead of organic solvents. Also, the glycerol is removed after the hydrolysis reaction so that the backward reaction between the glycerol and the ethyl ester disappears, and lead to the biodiesel yield and quality improvement. The aim of this study is making a comparison between our previous one-step process and the two-step reaction process to find the best pathway for designing and building an integrated reactor. Indeed, the two-step process is more applicable for low-grade feedstocks with a high amount of FFA and water.

Prevention of Cardiovascular Events with Omega-3 Polyunsaturated Fatty Acids and the Mechanism Involved.

An epidemiological study of Greenlandic Inuit suggested that fish oil, or omega-3 polyunsaturated fatty acids (PUFA), was important in preventing atherosclerotic disease. After this landmark study, many large-scale epidemiological studies and meta-analyses have examined the health benefits of omega-3 PUFA as part of a fatty acid-rich diet to demonstrate its beneficial roles in the prevention of cardiovascular diseases. Recent research has also focused attention on the anti-inflammatory effects of omega-3 PUFA and on specialized pro-resolving mediators. Findings of these studies have led to the development of omega-3 PUFA preparations for the treatment of dyslipidemia, including a highly purified eicosapentaenoic acid (EPA)-ethyl ester product (Epadel®) in Japan and an EPA/docosahexaenoic acid (DHA) preparation (Lotriga®) in the United States and Europe. Although various large-scale clinical trials on the cardiovascular preventive effect of omega-3 PUFA were conducted and reported, the results were not always consistent. The issues of not targeting subjects with hypertriglyceridemia and using low dose of omega-3 PUFA have been suggested to contribute to the failure of demonstrating the preventive effect of omega-3 PUFA in these clinical trials. Taking into account the above issues, the REDUCE-IT trial evaluated a highly purified EPA preparation at a high dose of 4 g/day in patients with hypertriglyceridemia and high cardiovascular risk, and demonstrated an extraordinary outcome of 25% relative reduction in cardiovascular events. This article reviews studies on omega-3 fatty acids during the last 50 years, including the progress in elucidating molecular mechanisms and recent large-scale clinical studies.