Luis Vázquez

Universidad Autónoma de Madrid, Química Física Aplicada, Faculty Member

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Discrimination against diacylglycerol ethers in lipase-catalysed ethanolysis of shark liver oil

Food Chemistry, 2013

Lipase-catalyzed ethanolysis of squalene free shark liver oil has been investigated. The mentione... more Lipase-catalyzed ethanolysis of squalene free shark liver oil has been investigated. The mentioned shark liver oil was comprised mainly of diacylglycerol ether and triacylglycerols. In order to test discrimination against diacylglycerol ether, up to ten different lipases were compared. The ratio oil to ethanol and lipase stability were also evaluated. Surprisingly, lipase from Pseudomonas stutzeri was the fastest biocatalyst among all assayed although poor discrimination against diacyl glycerol ether was attained. In this study, the best results in terms of selectivity and stability were obtained with immobilized lipase from Candida antarctica (Novozym 435). Ethanolysis reaction in the presence of Novozym 435 produced total disappearance of triacylglycerol and a final reaction mixture comprised mainly of diacyl glycerol ethers and monoacylglycerol ethers.

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A First Attempt into the Production of Acylglycerol Mixtures from Echium Oil

Frontiers in Bioengineering and Biotechnology, 2016

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Stearidonic Acid Concentration by Urea Complexation from Echium Oil

Journal of oleo science, 2018

Concentration of polyunsaturated fatty acids ethyl esters (FAEE) by urea complexation from Echium... more Concentration of polyunsaturated fatty acids ethyl esters (FAEE) by urea complexation from Echium oil was studied. Different variables involved in the process were investigated: amount and particle size of urea, solvent volume and ratio (hexane/ethanol), load of FAEE and reaction time. Hence, the main goal was to optimize SDA concentration (%) and yield (%) of stearidonic acid (SDA, 18:4 ω-3) and other bioactive FAEE. Similar behaviors were observed in fractionation between α-linolenic (ALA)-linoleic (LA), and γ-linolenic (GLA)-stearidonic (SDA) acids, attributed to similarities on their chemical structures, due to the position of the double bonds. At laboratory scale, the optimal conditions were 3 g urea (powder), 3.6 mL of hexane, 0.54 mL of ethanol and 800 mg of FAEE, during 20 h at 25°C. A scaling-up at pilot plant was carried out twice, obtaining more than 100 g of a final product, with ~29% SDA concentration and ~78% yield. Besides, after two washings with water, ethyl carbama...

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$Research paper thumbnail of Optimization of countercurrent supercritical fluid extraction conditions for spirits fractionation$

Optimization of countercurrent supercritical fluid extraction conditions for spirits fractionation

The Journal of Supercritical Fluids, 2001

Optimization of the countercurrent supercritical fluid extraction (CC-SFE) conditions to obtain d... more

Deacidification of olive oil by countercurrent supercritical carbon dioxide extraction: Experimental and thermodynamic modeling

Journal of Food Engineering, 2009

Supercritical carbon dioxide was used as an extractive solvent to remove free fatty acids from co... more Supercritical carbon dioxide was used as an extractive solvent to remove free fatty acids from coldpressed olive oil. Crude oil of different acidity content (from 0.5 to 4.0 wt%) was extracted in a packed column at 313 K and pressures of 180, 234 and 250 bar. The group contribution equation of state was employed to simulate the separation process, representing the oil as a simple pseudo-binary oleic acid + triolein mixture. Despite the simple representation of oil composition to simulate the deacidification process, a satisfactory agreement between the experimental and calculated yields and acidity of raffinates was obtained. The thermodynamic model was employed to study a continuous countercurrent multistage extraction process which yielded a raffinate having acidity lower than 0.7 wt%, when crude olive oil with different FFA content was processed.

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Fractionation of Short and Medium Chain Fatty Acid Ethyl Esters from a Blend of Oils via Ethanolysis and Short-Path Distillation

Journal of the American Oil Chemists' Society, 2010

The main objective of the present work was to obtain fractions enriched in short (SCFAEE) and med... more The main objective of the present work was to obtain fractions enriched in short (SCFAEE) and medium chain (MCFAEE) fatty acid ethyl esters (FAEE) from a blend of oils. For this purpose, coconut oil and dairy fat were blended and a transesterification of this blend was performed in order to transform the triacylglycerols into their corresponding FAEE. A detailed study of fractionation conditions for FAEE was carried out using short-path distillation. Different conditions were explored such as feed rates and temperatures; operating conditions, such as successive steps or a single step. The composition and yield of SCFAEE and MCFAEE were determined under different distillation conditions. Optimal fractionation of the desired compounds was achieved. High purity of SCFAEE and MCFAEE (94 wt%) was attained with a yield of *50%. An increased yield of SCFAEE and MCFAEE was achieved (85%) with a purity of 83 wt%. A broad range of high value fractions was obtained depending on the conditions selected. The fractions we obtained can be used as starting materials for the production of functional lipids.

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Concentration of Stearidonic Acid in Free Fatty Acids Form from Modified Soybean Oil by Selective Esterification with Dodecanol

Journal of the American Oil Chemists' Society, 2012

The concentration of stearidonic acid (SDA, 18:4 x-3) in free fatty acid (FFA) and fatty acid eth... more The concentration of stearidonic acid (SDA, 18:4 x-3) in free fatty acid (FFA) and fatty acid ethyl ester (FAEE) forms by low temperature crystallization (winterization) was studied. For this purpose, modified soybean oil (initial SDA content, *23%) was transformed into its corresponding FFA and FAEE by chemical hydrolysis and ethanolysis, respectively. In the first study, the FFA and FAEE were used as starting material for winterization and variables such as winterization time, type of solvent, and the oil:solvent ratio were evaluated until optimization of the process was achieved. In the second study, changes in the winterization procedure were introduced to obtain a remarkable improvement on the SDA purity of the final products. Since winterization of FAEE was not efficient due to its low melting points, the second study focused on FFA. The best relationship between SDA purity (59.8%) and SDA yield (82.3%) was attained by performing winterization of FFA with hexane at 10% oil:solvent ratio for 24 h. Scaled-up processes were also performed to obtain 59 g of FFA (purity 59.6%; yield 82.6%) enriched in SDA. The products obtained can be used as starting materials for the production of functional lipids and for clinical trials.

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Supercritical Carbon Dioxide Fractionation of Anhydrous Milk Fat

Journal of the American Oil Chemists' Society, 2014

Ethanolysis of shark liver oil was carried out to generate a product enriched in nonesterified al... more Ethanolysis of shark liver oil was carried out to generate a product enriched in nonesterified alkoxyglycerols and fatty acid ethyl esters. For the present study, the original oil contained very low amounts of squalene, and thus, unsaponifiable matter was mainly constituted by nonesterified alkoxyglycerols (NEAKG). A small percentage of monoesterified alkoxyglycerols (MEAKG) was also detected. Supercritical fluid extraction was employed to fractionate the mixture, achieving a complete elimination of esters and concentrating the alkoxyglycerol compounds in the raffinate product. Extractions were carried out in a countercurrent packed column, using extraction pressures in the range of 140-180 bar, temperatures from 45 to 65°C, and a solvent-to-feed ratio of 15. NEAKG + MEAKG purity obtained in the raffinate at the best extraction conditions was around 78% w/w, and satisfactory yield (>60%) was also achieved. Therefore, the raffinate product can be re-esterified to design highly valuable ether lipid compounds.

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