Sagrario Beltrán

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Verified

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• PhD
• Professor (Full) at University of Burgos

The lactic acid (LA) production from corn stover using Lewis acid catalysts was optimized. Initially, an equimolar mixture of Al(III)/Sn(II) was used as a catalytic system at 190 °C with 5 wt% biomass. Increasing the catalyst concentration led to higher LA production, showing the optimal results at 16 mM. A low catalyst concentration mainly produce...

This study optimizes lactic acid (LA) production from corn stover using a Lewis acid catalyst. Initially, an equimolar mixture of Al(III):Sn(II) was used as catalyst at 190 °C with 5 wt. % biomass. Increasing catalyst concentration led to more LA, with optimal results at 16 mM, between 5 and 32 mM. Low catalyst concentration produced mainly dehydra...

The optimization of hydrothermal lactic acid (LA) production from corn stover using Ca(OH)2 as catalyst was investigated. Initial studies with a 9 g L⁻¹ glucose solution, and different Ca(OH)2 concentrations, in the range of 0.025–0.1 m, identified 0.075 m as the optimal concentration. Ca(OH)2 acted both as catalyst and reactant, neutralizing LA, a...

Two different hydrolysates of the water-soluble protein (WSP) fraction from tuna fish meal were obtained by subcritical water-CO 2 (subW-CO 2 ) and Alcalase ® treatments. Hydrolysates showed different chemical composition regarding their free amino acid (FAA) profile and molecular weight distribution of the peptides generated. Consequently, differe...

Gelidium sesquipedale is valued in the Spanish agar industry, but its production generates substantial waste, often discarded despite its nutritional and bioactive content. Subcritical water extraction (SWE) at 175 °C and 50 bar for 130 min was performed on this waste after agar extraction, comparing it to conventional ethanol extraction. The SWE e...

Subcritical water (SCW) hydrolysis was applied to valorize the low-valued ray-finned fish (Labeobarbus nedgia) into valuable protein hydrolysates, employing N2 and CO2 as pressurization agents at varying temperatures (140, 160, 180, and 200 °C). The degree of hydrolysis (DH) and total free amino acid content increased with temperature for both pres...

Lanthanides were tested (Ce³⁺, Er³⁺, and Yb³⁺) as catalysts to produce lactic acid (LA) from the monosaccharides present in corn stover (glucose, xylose, and arabinose) resulting in ytterbium being the most active. A MW-heated system led to similar LA yield as a conventionally heated pressurized system. The maximum value of LA yield was 40% at 240...

Onion skin waste (OSW), the primary non-edible byproduct from onion processing, offers a renewable source of bioactive compounds. This study aims to valorize OSW through subcritical water extraction (SWE), aligning with a circular economy and biorefinery principles. SWE was carried out at 145 °C and 50 bar for 50 min in a discontinuous reactor, pro...

Onion skin waste (OSW), the primary non-edible byproduct from onion processing, offers a renewable source of bioactive compounds. This study aims to valorize OSW through subcritical water extraction (SWE), aligning with circular economy and biorefinery principles. SWE was carried out at 145 °C, 50 bar and 50 min in a discontinuous reactor, producin...

Lanthanides were tested (Ce ³⁺ , Er ³⁺ , Yb ³⁺ ) as catalysts to produce lactic acid (LA) from the monosaccharides present in corn stover (glucose, xylose and arabinose) resulting in ytterbium being the most active. A MW-heated system led to similar LA yield as a conventionally-heated pressurized system. The maximum value of LA yield was 40% at 240...

The hydrolysis of the water-soluble protein (WSP) fraction from tuna fish meal was evaluated by subcritical water (subW) by using N2 and CO2 as different pressurization agents in the temperature range from 140 to 180 °C. For both gases, the amino group release increased by increasing working temperature while the Lowry response decreased due to pro...

The feasibility of industrial subcritical water treatment on Gelidium sesquipedale residue through scaling up from the lab to pilot system in discontinuous mode (geometric scale-up factor = 50), at 130 and 175 °C (5% biomass), was investigated. The maximum volumes of the reactors were 500 mL at the lab-scale and 5 L at the pilot-scale system. At 17...

The feasibility of an industrial-scale subcritical water (SW) system by scaling up from laboratory to pilot scale in a discontinuous operation mode has been investigated regarding the valorization of brewer´s spent grain (BSG). The subcritical water treatment (SWT) of BSG at the pilot scale in a discontinuous mode at 170 °C and 22 min, resulted in...

This work is focused on the development of sustainable process for the valorisation of the main by-product generated in the brewing industry brewer’s spent grain (BSG). A two-step process combining subcritical water treatment and pervaporation (PV) was proposed to hydrolyse the hemicelluloses fraction of this lignocellulosic biomass and further rem...

Bioeconomy and environmental issues envisage industrial by-products such as Brewer’s spent grain (BSG) as renewable resources for their recycling and reuse within a biorefinery concept. This study aimed to investigate the production of bioethanol from subcritical water (subW) pretreated BSG, following the conversion of the BSG biopolymers cellulose...

A significant amount of bioactive compound-rich solid waste is released during the industrial phycocolloid-centric extraction of Gelidium sesquipedale. The impact of mild pressurized hot water extraction on repurposing this waste for the recovery of agar with an adjustable gel texture is investigated. A two-factor interaction response surface model...

An ultrafiltration-based process for oligosaccharide and peptide fractionation from a macroalgae subcritical water hydrolysate was studied. A wide range of separation results was obtained depending on the membrane pore. 100 kDa cut-off size was enough for hydrolysate clarification with total retention of colloidal materials. Oligosaccharides presen...

The double effect of supercritical carbon dioxide, sc-CO2, in a biorefinery concept applied to brewer’s spent grain (BSG) was assessed in this work. Extraction conditions to remove and valorize the lipophilic fraction were studied (20 – 40 MPa and 40 - 80 °C) obtaining a maximum yield of 5.70 ± 0.07 g /100 gBSG at 80 °C and 40 MPa. High pressures a...

The potential of using pressurized hot water extraction to valorize the remaining crude agar in Gelidium sesquipedale waste stream after an initial industrial extraction was investigated. In this process, a four-factor Box-Behnken design was coupled with a response surface methodology. The impact of the operating temperature (°C), the internal pres...

The semi-continuous hydrolysis of onion skin wastes (OSW) using subcritical water (SubW; working conditions: 105-180 ºC; 5 MPa; 2.5 mL/min) has been studied in this work. Liquids after hydrolysis showed a sharp increase in total organic carbon (>30 mg/g OSW) at temperatures above 145 ºC, when SubW began to promote the partial hydrolysis of the stru...

In this study, we aimed to prepare stable water-in-oil (W/O) nanoemulsions loaded with a phenolic-rich aqueous phase from olive cake extract by applying the response surface methodology and using two methods: rotor-stator mixing and ultrasonic homogenization. The optimal nanoemulsion formulation was 7.4% (w/w) of olive cake extract as the dispersed...

The valorization of the underexploited solid residue after agar extraction from red marine algae was studied by subcritical water treatment. Experiments were carried out in two different semi-continuous fix-bed reactor configurations at 185 ºC at different subcritical water residence times. The use of a by-pass section allowed to heat the water pre...

In this work, the intensification of the extraction of flavonoids from dry onion skin wastes (DOSW) by Ultrasound Assisted Extraction (UAE) was investigated. Conventional stirred tank extraction was used to find the optimal temperature (37 °C) and solvent (ethanol 70%, v/v), providing 20.7 ± 0.4 mg QE/g DOSW after 1 h. In the UAE process, the ampli...

A complete chemical characterization of Moringa oleifera leaves was carried out showing a high content of extractives. Extraction kinetics of bioactive compounds present in this fraction were performed by conventional and ultrasound assisted extraction (UAE). A 50 % (v/v) hydroalcoholic mixture led to the highest total phenolic compounds yield by c...

Olive pomace, a solid residue generated during olive oil production process and a rich source of phenolic compounds, was dried and defatted to obtain a pomace oil rich in monounsaturated fatty acids with 64% oleic acid. The defatted pomace was further treated by ultrasound-assisted extraction (UAE). The optimal phenol extraction conditions of 10 mi...

In this work valorization of the underexploited industrial solid residue generated after agar extraction from Gelidium sesquipedale was studied by using subcritical water in a semicontinuous fix-bed reactor. First, a complete characterization of this by-product was carried out, determining up to 21% (w/w) of protein content (for a nitrogen factor o...

Driven by growing prevalence of chronic diseases and consumer’s health awareness, food supplements and nutraceuticals based on omega-3 polyunsaturated fatty acids (PUFAs) are extensively marketed nowadays. However, commercial omega-3 concentrates still present quality issues related to their purity, bioavailability, and easily-oxidizable nature, co...

The valorization of the brewery’s spent grain (BSG) generated in a craft beer industry was studied by subcritical water hydrolysis in a semi-continuous fixed-bed reactor. Temperature was varied from 125 to 185 °C at a constant flow rate of 4 mL/min. Biomass hydrolysis yielded a maximum of 78 % of solubilized protein at 185 °C. Free amino acids pres...

The efficiency of enzymatic hydrolysis for the release of different biocompounds such as total phenolic compounds (TPC), sugars and proteins from the industrial solid residue of G. sesquipedale after agar extraction has been evaluated. Cellulase (0.25% - 8%, w/w, enzyme: solid residue, pH = 5) has been proved to be an efficient enzyme to degrade th...

The valorization of onion skin wastes (OSW) through the extraction, identification, and quantification of phenolic compounds was studied in this work, using subcritical water in a semicontinuous extractor (2.5 mL/min; 105–180 °C; 5 MPa). The extraction of flavonoids resulted to be fast (<30 min) and temperature sensitive (maximum at 145 °C; total f...

Valorization of olive leaves (OL) in a biorefinery context should include extraction of bioactive compounds, specially taking into account the high content of extractives of this by-product. Extraction of bioactive compounds from Spanish OL (cultivar “Serrana de Espadán”) was studied by conventional and ultrasound assisted extraction (UAE). Faster...

We report on the preparation, characterization, and foaming behavior of cellular polymers based on 1-vinyl-2-pyrrolidone (VP) and methyl methacrylate (MMA). Samples with different feed ratios proportions of VP and MMA were prepared following the bulk radical copolymerization procedure, using commercially available monomers and testing two different...

A wheat bran oily extract obtained with supercritical carbon dioxide at 25.0 ± 0.1 MPa and 40 ± 2 °C has been analyzed in order to determine some valuable bioactive compounds as alkylresorcinols, α-linolenic acid, steryl ferulates, tocopherols and phenolic compounds, which levels were around 47, 37, 18, 7 and 0.025 mg/g oily extract, respectively....

High‐pressure carbon dioxide and thermosonication technologies were applied to cloudy apple juice to determine their effect on polyphenol oxidase (PPO) and pectin methylesterase (PME) activity and other quality parameters right after the treatment and during storage at 4ºC for 28 days. Treatment conditions were 20 MPa, 45ºC, for 60 min and 20 kHz,...

In this work, the encapsulation of rice bran oil extracted using supercritical CO2 has been studied. In the first stage, the emulsification process by high pressure homogenization was studied and optimized. The effect of the working pressure (60–150 MPa), the composition of the carrier (mixtures of pea protein isolate (PPI) and maltodextrin (MD), f...

Brewer’s spent grain (BSG) was chemically characterized obtaining 52.1% of carbohydrates, 17.8% protein, 5.9% lipids, 13.5% insoluble lignin and 24.3% of water-soluble extractives. This work has been focused on the study of polyphenol extraction of the extractive fraction by water ultrasound-assisted extraction. Selected extraction conditions were...

The use of supercritical CO2 (ScCO2) has been established as a standard technique to produce micro- and nanocellular polymers with controlled morphologies and cell sizes between 500 nm and several microns. However, overcoming the gap between micro and nanocellular polymers implies the use of long saturation times (up to several days) and low temper...

Polyphenoloxidase from apple was extracted and further concentrated by cationic reversed micellar extraction. Previous to reversed micellar extraction a crude protein extract was obtained using AG2-X8 as adsorbent of phenolic compounds and the detergent Triton X-100. Forward and backward extraction conditions were optimized by using dodecyl trimeth...

Quinoa has recently been considered as an alternative oilseed crop due to the quality and quantity of its lipid fraction. Supercritical fluid extraction (SFE) was used as a green process to extract quinoa oil without solvent residues. Defatted quinoa flour is a potentially valuable raw material whose performance as food ingredient needs to be estab...

In this work, as a first step in a comprehensive strategy for the valorization of rice bran, the extraction of oil using supercritical CO2 and ethanol as cosolvent has been studied. The effect of extraction temperature (40 and 60 °C), pressure (30 and 40 MPa) and amount of ethanol used (0, 5 and 10%) has been considered. The quality extracted oil h...

Supercritical carbon dioxide (SC−CO2) has been used as solvent in the ethanolysis of fish oil rich with omega-3 polyunsaturated fatty acids (n-3 PUFAs) by Lipozyme 435. The effect of experimental conditions: initial ethanol-to-oil molar ratio (MR, 6:1-76:1), pressure (10–30 MPa), and temperature (323–343 K) on the reaction performance has been stud...

Aim of Study: The use of a nebulizer paired with high-flow nasal cannulas (HFNC) has been proposed for drug delivery in bronchiolitis. Particle size nebulized is a relevant factor determining the efficacy of the nebulization. We replicated in vitro the theoretical parameters most widely used in bronchiolitis and we compared the size of the droplet...

The extraction of polyphenoloxidase (PPO) from Litopenaeus vannamei was studied at different temperatures, pH and ionic strength conditions. Optimum extracts at pH = 7.2 were treated by hiph pressure carbon dioxide (HPCD) technology at 20 MPa and in a temperature range from 35 to 50 °C. Inactivation kinetics for PPO extracts were determined and fit...

Particles from Gas-Saturated Solutions (PGSS)-drying has been used as a green alternative to encapsulate omega-3 polyunsaturated fatty acids (n-3 PUFAs) at mild, non-oxidative conditions. PGSS-dried particles have been compared to those obtained by conventional drying methods such as spray-drying and freeze-drying, finding encapsulation efficiencie...

In the present work, High Pressure Carbon Dioxide (HPCD) has been used to inactivate the enzymes Polyphenol Oxidase (PPO) and Pectin Methylesterase (PME). The work has been done in two stages: in the first one, fundamental knowledge about the inactivation mechanism induced by HPCD was obtained using pure commercial enzymes. The influence of the mai...

In the present work the effect of High Pressure Carbon Dioxide (HPCD) on the activity and structure of a commercial pectin methylesterase (PME) was studied and the results were compared to the conventional thermal inactivation technology. The use of supercritical CO2 (pressure 6–18 MPa, temperature 40–55 °C and time up to 75 min) increased dramatic...

Measurements of CO2 solubility were performed in different media, pure water, model citrate buffer solutions at different pH values and in the presence of different sugar content and in real apple and carrot juices. Solubility was determined in the pressure range from 8 to 20 MPa and in the temperature range from 308 to 318 K. CO2 solubility in cit...

Tyrosinase from mushroom was used as a model polyphenol oxidase (PPO) enzyme to perform a systematic inactivation study using High Pressure Carbon Dioxide (HPCD). The ratio CO2/volume of enzyme (g/mL) loaded in the reactor was found to be critical. Above a critical ratio, pressure, temperature and time did not control the inactivation performance....

A series of cross-linked copolymer films based on 1-vinyl-2-pyrrolidone and methyl methacrylate were produced using different poly(ethylene glycol) dimethacrylates as cross-linking agents. The average molecular mass of the cross-linking agent was varied, then allowing the foaming process using supercritical CO2 (ScCO 2), obtaining mi-crocellular fi...

Tomato juice, Lycopersicon esculentum cv. Canario, has been treated by high pressure carbon dioxide (HPCD) as non-thermal preservation treatment. The inactivation kinetics for pectinmethylesterase (PME) and polygalacturonase (PG) were determined at different pressures (8.5–20 MPa) and temperatures (35–55 °C). At the highest operating pressure and t...

Oxidation kinetics of sardine oil have been determined at 40, 65 and 90 °C by measuring concentration of primary and secondary oxidation products in the presence of commercial immobilized lipases (Lipozyme 435, Lipozyme RM and Lipozyme TL) commonly used as biocatalyst in lipid modification reactions. Oxidation products concentration was found to be...

The supercritical CO2 extraction of oil from four different quinoa varieties has been studied in this work. For this purpose, the influence of extraction temperature (40–60 °C), pressure (20–40 MPa) and raw material size (250–1000 μm) on the extraction rate has been considered. The extraction rate resulted to be faster the higher the pressure where...

Cloudy apple juice has been treated by thermosonication in batch mode as an alternative processing to thermal treatment. Thermosonication was found to be effective to inactivate polyphenol oxidase; however, pectinmethylesterase was found to be more resistant. An increase of the working ultrasound amplitude and the amount of energy supplied to the j...

Cloudy apple juice has been treated by high pressure carbon dioxide (HPCD) as non-thermal technology to inactive polyphenoloxidase and pectinmethylesterase in batch mode. Stirring speed (from 200 to 600 rpm) induced an increase in the enzyme inactivation rate while a triple cycle of pressurization/depressurization led to the same enzyme inactivatio...

Mono- and diacylglycerols rich in omega-3 have a great interest due to their good bioavailability and oxidation stability compared with other kind of omega-3 concentrates. The main drawback in mono- and diacylglycerols production by glycerolysis is the immiscibility of the substrates, oil and glycerol. To improve mass transfer rates, avoiding the u...

This work provides experimental fluid phase equilibrium data of the pseudo-ternary mixture CO2 + ethanol + fish oil, a system of interest in pharmaceutical and food-industry applications such as the production of omega-3-enriched lipid derivatives at mild, non-oxidative conditions. Experimental tie-lines were obtained by means of an analytical isot...

Supercritical carbon dioxide (SC-CO2) has been used as green solvent in the lipase-catalyzed ethanolysis of fish oil by Lipozyme RM IM at mild, non-oxidative conditions and with no solvent residues. The effect of experimental conditions, initial substrate ethanol/oil molar ratio (2-38), pressure (7.5-30 MPa), and temperature (323.15-353.15 K) on eq...

The volatiles emitted from the fresh and dry leaves, determined by solid-phase-micro-extraction (SPME), the essential oils obtained by hydro-distillation and supercritical-fluid-extraction (SFE) from the leaves of Origanum syriacum L. (Lamiaceae), grown in Jordan, were analyzed by GC-MS. In all applied methods, oils were rich in monoterpenes, while...

Inactivation of pectinmethylesterase (PME) and quality parameters of orange juice have been studied after high pressure carbon dioxide (HPCD) treatment. The HPCD treatment conditions covered a wide range of temperature from 2 to 40 °C, far below normal thermal treatment, while operating pressure was varied from 10 to 30 MPa and exposure time from 3...

Production of monoacylglycerols (MAGs) rich in ω-3 polyunsaturated fatty acids (n-3 PUFAs) was conducted through short path distillation (SPD) of an acylglycerol mixture (containing 67% MAGs) produced by enzymatic glycerolysis of sardine oil with glycerol. A stepwise SPD process in a UIC KDL 5 system (vacuum 10(-3)mbar, feeding flow 1.0mL/min) was...

The production of polyunsaturated fatty acids (PUFAs) concentrates by enzymatic catalysis has gained interest due to their stereospecificity and the milder conditions employed compared to the use of inorganic catalysts. The enzymatic glycerolysis of sardine oil by Lipozyme® 435 to get PUFA concentrates in the forms of di- and monoacylglycerols (DAG...

The solubilization process of sorbitan monooleate (Span 80) niosomes, formed by sonication, by addition of the anionic surfactant sodium dodecyl sulfate (SDS) was studied in this work. The main parameters studied were the optical density at 350 nm wavelength, particle size distribution, zeta potential, and the concentration of SDS monomers in the d...

The production of monoacylglycerol rich in polyunsaturated fatty acids (PUFA) via enzymatic glycerolysis of sardine oil in a homogeneous system was evaluated. Reactions were conducted in two different tert-alcohols. Based on the phase equilibrium data, the amount of solvent added to create a homogeneous system has been calculated and optimized. The...

The ethanolysis of fish oil in various reaction medium (tert-pentanol, n-hexane and solvent free system) catalyzed by the immobilized commercial lipase Lipozyme(®) 435 (Candida Antarctica) at atmospheric pressure has been studied in this work. The effect of some kinetic parameters, such as the amount of lipase, temperature and the initial reactant...

Wheat bran oil (WBO) has been reported to have an important content of bioactive compounds, such as tocopherols, alkylresorcinols, steryl ferulates and other phenolic compounds; however, its poor solubility in water systems restricts its applications in the food industry. This study is focussed on the formulation of oil-in-water (O/W) nanoemulsions...

Triacylglycerols (TAG) of two different refined fish oils from sardine and a mixture of tuna and sardine oil were separated by reverse phase high performance liquid chromatography (RP-HPLC) with a binary solvent gradient of acetone/acetonitrile. Different fractions were observed in the chromatogram and TAG species were tentatively identified by sub...

The supercritical fluid extraction (SFE) of wheat bran oil with pure supercritical carbon dioxide at different extraction pressure (25, 40 and 55 MPa) and temperature (40, 70 and 95 °C) has been studied. Since wheat bran is characterized by having an important content of bioactive compounds such as alkylresorcinols (AR) and other phenolic compounds...

The supercritical fluid extraction (SFE) of wheat bran alkylresorcinols has been studied. Extractions were carried out at 40.0 MPa. The effect of particle size, static extraction pretreatment with supercritical CO2 (SC-CO2) and extraction temperature on the extraction kinetics was investigated. The extraction yield increased as the particle size de...

Monoacylglycerols (MAGs) can be produced by lipase-catalyzed glycerolysis of oils and fats at atmospheric pressure and low temperature. The use of organic solvents as reaction media helps to create a homogeneous reaction system between the immiscible reactants glycerol and oil. In this work liquid-liquid equilibrium at two different temperatures (3...

Enzymatic alcoholysis of fish oil can produce monoacylglycerols rich in polyunsaturated fatty acids at atmospheric pressure and low temperature. Biocatalysis in organic solvents helps to create a homogeneous reaction system for the reactants, ethanol and fish oil. This work presents liquid–liquid equilibrium at two different temperatures (303.2 K a...

Pervaporation has been used to obtain aroma concentrates from brown crab boiling juice. The boiling juice and the obtained permeate have been analysed by Headspace Solid Phase Dynamic Extraction Gas Chromatography/Mass Spectrometry. The effect of feed temperature on the pervaporation performance of the membrane has been analysed. The permeate aroma...

Pervaporation experiments with PERVAP™4060 membrane have been performed to study its ability to concentrate some aroma compounds identified in the brown crab boiling juice from a model dilute aqueous solution. The effect of feed concentration, pervaporation temperature and permeate pressure on the pervaporation performance of the membrane has been...