Maria Jose Cocero

• Dr
• Professor (Full) at University of Valladolid

The paper and pulp industry annually generates approximately 170 million tons of black liquor, yet research directly targeting its utilization remains scarce. Addressing this gap, our study tackles the challenge of revalorizing black liquor through innovative techniques. Concurrently, the lubricant industry’s pursuit of eco-friendly alternatives ne...

Re-polymerization reactions are a commonly reported issue on the way to the higher recovery of monomers from lignin. The reactivity of monomers obtained from lignin depolymerization and their contribution to the re-polymerization in supercritical water (SCW) was investigated. Sulfonated Kraft lignin (SKL) was used along with four monomers: vanillin...

Different lignins from different sources (hardwoods, softwoods and crop residues) and obtained as by-products of different processes such pulping or biorefining were depolymerized in alkaline supercritical water (SCW: 386 °C and 260 bar) in an intensified continuous process to produce high value-added compounds with low-molecular-weight in only 300...

Natural products are used by the food, pharmaceutical and cosmetics industries, and extraction technologies and potential applications for plant extracts are of interest to many industrial sectors. Extraction of natural products in an economic and environmentally friendly way is of high importance to all industries involved. The second edition of t...

This work discusses hydrolysis of defatted grape in supercritical water (SCW) at 380 °C and 260 bar from 0.18 s to 1 s focusing attention to sugars recovery in the liquid phase of the product and detailed characterization of remaining solid phase enriched in polyaromatics (e.g. lignin, flavonoids, etc.). After the longest reaction time of 1 s, 56%...

In this work, the ionic liquid [Aliquat][Cl] was supported into alginate and silica aerogel matrices and applied as a catalyst in the cycloaddition reaction between CO2 and a bio-based epoxide (limonene oxide). The efficiency of the alginate aerogel system is much higher than that of the silica one. The method of wet impregnation was used for the i...

The potential of saffron flowers as a source of polyphenols, and in particular anthocyanins, for the extraction of bioactive compounds and the production of a cyanic colorant was analyzed. A microwave pretreatment, prior to the conventional solid–liquid extraction process, was proposed as a feasible intensification step. The effectiveness of microw...

Residues of the tobacco industry are a source of valuable compounds such as solanesol and nicotine. In this work, the supercritical fluid extraction of these compounds from tobacco scrap was studied. The effect of the key process parameters (pressure, temperature, extraction time) was analyzed and a phenomenological model of the extraction was appl...

Açaí (Euterpe oleracea Mart.) is a berry found in Amazon Rainforest. Due to its increasing commercial value, the cultivation of this fruit in northern Brazil is growing quickly, and with it the increasing production of waste by this industry also poses a growing problem. This study presents a characterization of all residual fractions of the indust...

Açaí (Euterpe oleracea Mart.) is a black-purple berry, typically found in Amazon Rainforest, and a natural phytochemical source, which shows a high content of polyphenols and flavonoids, with remarkable properties as an antioxidant, anti-inflammatory, antimicrobial, and natural dye. The precipitation and encapsulation of Açaí extracts with biopolym...

Kraft lignin was rapidly depolymerised in a continuous reactor using sub- and supercritical water. The reaction yielded an aromatic oil rich in high value aromatic monomers such as guaiacol, vanillin, acetovanillone and homovanillic acid. Different temperatures between 300 and 400 °C and reaction times from 60 ms were studied. An increment in react...

Arbutus unedo L., commonly known as the strawberry-tree fruit, is an endemic species of the Mediterranean flora. Microwave extraction technology has been considered as a fast and “green” method for the production of extracts rich in bioactive compounds, although the energy consumption is high. To overcome this bottleneck, microwave was used as a pr...

Rosmarinus officinalis and Zataria multiflora (Lamiaceae) essential oils (EOs) contain components with insecticidal properties that can be used as pesticides for stored product pests. In the present study, they were encapsulated in octenyl succinic anhydride (OSA) - starch in order to test their insecticidal activity against Tribolium confusum. Fir...

Phenolics present in grapes have been explored as cosmeceutical principles, due to their antioxidant activity and ability to inhibit enzymes relevant for skin ageing. The winemaking process generates large amounts of waste, and the recovery of bioactive compounds from residues and their further incorporation in cosmetics represents a promising mark...

In a biorefinery approach, inulin and inulin-rich biomass as Jerusalem artichoke (JA) could be transformed into platform chemicals such as fructose and/or pyruvaldehyde. To do so, the FASTSUGARS pilot plant proved to be a promising alternative for the selective conversion of biomass. In this work, inulin and JA were hydrolyzed in supercritical wate...

This work analyzes the influence of the mixer configuration on the mixing efficiency in the process of biomass ultrafast hydrolysis by supercritical water. The results of the CFD simulations of a horizontal tee, a vertical tee and a cross mixer, selected as the optimal mixing configurations, together with the experimental results obtained in our hy...

Caffeine and carvacrol were encapsulated using supercritical CO2 (sc-CO2) impregnation in MOFs, MIL-53(Al) and Mg-MOF-74, at different contact times. High additive loadings were achieved, 32.1 and 34.3% for caffeine, and for carvacrol 34.4 and 30.1%, respectively. The sc-CO2 encapsulation was more effective compared to the typical liquid phase enca...

This article seeks to be a handy document for the academy and the industry to get quickly up to speed on the current status and perspectives of biomass pretreatment for biorefineries. It is divided into two biomass sources: veg-etal and animal. Vegetal biomass is the material produced by plants on land or in water (algae), consuming sunlight, CO 2...

Nowadays, the valorization of lignin, the major natural source of aromatics in earth, is being a challenge for the scientific community. In this study, kraft lignin is effectively converted into aromatic monomers by ultrafast depolymerization in hot and pressurized water. At reaction times below 500 ms, it is possible to avoid char formation origin...

Açaí (Euterpe Oleracea mart.) is a berry found in Amazon Rainforest, with a high content of polyphenols and flavonoids. This work studied the formulation of bioactive compounds extracted from E. Oleracea fruit, by impregnation in silica-aerogel. Three fruit fractions were studied: pulp, seeds and slurry, and two extracts were obtained from each fra...

This paper discusses the influence of reactor design and initial consistency when partially hydrolyzing microcrystalline cellulose (MCC) in supercritical water. Experiments conducted on two pilot reactors located in Finland and in Spain showed that stopping the reaction using depressurization instead of quenching, combined with a sufficiently high...

Surface Plasmon Resonance can be used to activate zinc oxide/copper catalysts in order to perform the carbon dioxide hydrogenation reaction by means of light energy, avoiding high-temperature processes. The synthesis and impregnation methods have been designed to fill glass microreactors with ZnO/Cu nanoparticles supported on transparent silica aer...

Maltodextrin (MD), whey protein isolate (WPI) and pea protein isolate (PPI) have been used in this work as carrier agents in the spray drying of grape marc extract, and the obtained microparticles have been characterized in terms of drying yield, morphology (SEM), size distribution, chemical structure (FTIR), chemical composition (total phenolic an...

Sugar beet pulp (SBP) is the major by-product in sugar industry. To make profit out of this undervalued residue, the FASTSUGARS process was proposed as a solution, combining the advantages of supercritical water as hydrolysis medium with very short reaction times in the so-called ultrafast reactors. Operating at 390 °C, 25 MPa and reaction times be...

Wine lees are rich in anthocyanins (AC), natural colorants with health promoting properties. The extraction kinetics of AC from different wine lees in conventional solid–liquid extraction were studied for the first time. The influence of parameters such as temperature, solid–liquid ratio (RS-L) and type of solvent (hydro-alcoholic mixtures) was als...

This study re-analyzes literature data on S. platensis’ chlorophyll (CHL) extraction using 5-25 cm3 of 20-80% v/v ethanol in water (static modifier) and 82.5-62.5 cm3 of CO2 at 50 °C and 40 MPa. Under these conditions, a CO2-expanded aqueous ethanol (liquid) phase coexists with an aqueous-ethanol-modified CO2 (SCF) phase in the extraction vessel. A...

This study presents a thermoeconomic and environmental assessment of the extraction of lipids and proteins from wet microalgal biomass in a 3G biorefinery by two different technologies: supercritical fluid extraction (SFE) and low-pressure solvent extraction (LPSE). Simulation tools were used to study a sugarcane biorefinery producing ethanol from...

The FASTSUGARS process for sugars’ recovery from agricultural biomass was scaled up from laboratory to pilot plant scale. System performance was evaluated by comparing the results obtained from sugar beet pulp and wheat bran in laboratory and pilot plants. Similar trends were found for each biomass in both plant: as reaction time increased, selecti...

Herbal medicinal plant have been recognized as alternative and natural drugs for therapeutic purposes due to their high content of phytocompounds with anti-bacterial, antioxidant and anti-inflammatory properties. Low solubility and poor absorption of medicinal compounds are seen as major challenges for herbal drugs. Impregnation of these substances...

Conventional kinetic models of cellulose hydrolysis in supercritical water do not accurately represent the operation with concentrated suspensions since they neglect the mass transfer effects. This work proposes a kinetic model which is able to reproduce cellulose hydrolysis at high concentrations providing the optimum reaction conditions to obtain...

A combined process of supercritical water oxidation (SCWO) and supercritical water hydrothermal synthesis (SCWHS) in a continuous counter current reactor is reported. Acrylic acid was used as a model unsaturated carboxylic acid compound and the effects of the reaction temperature, residence time, oxidant ratio and acrylic acid concentration on chem...

Thermodynamic modeling in CFD is basically limited to the models available in the simulators. The method presented in this paper connects CFD simulators with Aspen Plus which instantaneously calculates and returns the value of any physical property required. Therefore, all the thermodynamic models and compounds available in Aspen Plus can be implem...

Aging wine lees are water-wastes produced during the wine aging inside wood barrels that can be considered as alternative sources of bioactive compounds. Phenolic characterization and antioxidant activity (AA) measurements of wines lees solid-liquid extracts have been undertaken on a dry extract (DE) basis. Solvents with different polarities (water...

This study aims to develop a formulation of a turmeric-based dye extract using supercritical antisolvent (SAS) technology and different encapsulating polymers to improve the aqueous stability and solubility of curcumin. The dye formulation obtained by SAS consists of a mixture of Eudragit® L100 and Pluronic® 127 using tween 20 as a surfactant The c...

The objective of this study was to elucidate the effect of adding acid and alkali to hydrothermal liquefaction (HTL) of two waste biomass feedstocks—manure digestate and carbohydrate-rich food waste. HTL reactions were conducted at 300 °C for 60 min, with and without the addition of acid or base. We measured the quantity and characterized the quali...

Polysaccharide aerogels are a good alternative as carriers for drug delivery, since they allow high loading of the active compounds in matrices that are non-toxic, biocompatible and from a renewable feedstock. In this work, barley and yeast β-glucans aerogels were produced by gelation in aqueous solution, followed by solvent exchange and drying wit...

s This contribution examines the challenges faced by supercritical water processes for industrial development. As an alternative, the intensification of the supercritical water processes is presented in order to reduce the size of the equipment needed and to facilitate the scaling up of the process. The perspective of developing micro combustors us...

The most frequent polymer on nature is cellulose that is present together with lignin and hemicellulose in vegetal biomass. Cellulose can be, in the future, sustainable raw matter for chemicals, fuels, and materials. Nevertheless, only 0.3% of cellulose is processed nowadays due to the difficulty in dissolving it, and only a small proportion is use...

New experiments of cellulose acetylation were performed using the ionic liquid 1-allyl-3-methylimidazolium chloride ([Amim]Cl) as a solvent, at temperatures of 80, 60 and 40°C. An attempt is done to improve the performance of the reaction by pressurizing the reaction with 80bar of CO2. The results indicate that scCO2 speeds up the kinetics of the r...

In this study, we discuss the difference regarding thermo-economic and environmental (water intake) aspects between two methods of biomass hydrolysis. A thermo-economic model was developed using Aspen Plus® and MATLAB software in order to analyze the energy efficiency, as well as, the economic impact of the hydrolysis process integrated into a trad...

Microwave assisted extraction advantages are widely recognised. However, its implementation at industrial scale is restricted due to microwave limitations. In this work, a microwave pretreatment is proposed as an easy scale-up alternative for grape pomace polyphenol extraction, especially for anthocyanins. The double effect of this pretreatment on...

Production of lipid particles loaded with metal nanoparticles by supercritical fluids based processes has been barely studied. In this work, copper nanoparticles were loaded into glyceryl palmitostearate microparticles by PGSS® (Particles from Gas Saturated Solutions). The effect of different variables, temperature (60–80 °C), copper load (0.2–5%w/...

Biomass fractionation into its individual building blocks poses a major challenge to the biorefinery concept. The recalcitrance of the lignocellulose matrix and the high crystallinity of cellulose make typical feed stocks difficult to separate into their components. Hydrothermal processing fractionates biomass by its hydrolysis. However, a deep kno...

Barley and yeast β-glucans were selected, together with lecithin, to encapsulate resveratrol by emulsification-evaporation method to develop new and safer antifungal formulations. Different emulsification techniques were used: high-shear, high pressure and high pressure and temperature emulsification. Morphology, crystallinity, encapsulation effici...

The supercritical water hydrolysis (SCWH) of biomass (P = 250 bara & T = 400 °C) allows directly obtaining sugars, which are high value products in the chemical industry, in reaction times lower than 0.2 s. The process is characterized by the high selectivity values which can be obtained controlling the reaction time. Reaction kinetics show that gl...

The use of natural polysaccharides is especially attractive to the pharmaceutical industry because of their stability, availability, renewability and low toxicity. In this study, cellulose aerogels obtained from cellulose/ionic liquid solutions were prepared by supercritical drying with surface areas ranged from 154 to 434 m² g⁻¹, pore volume from...

The present work focuses on the study of fluidization of nanoparticle agglomerates with SC-CO2 at different temperatures (308–320 K) and pressures (7.7–14.4 MPa). These conditions allow this work to be carried out in a wide range of densities, varying from 200 to 800 kg/m³. Three materials with different bulk densities were tested: aluminum oxide (...

It is believed that climate change will greatly impact the relative importance of pests. The bird cherry-oat aphid, Rhopalosiphum padi L. is probably the major pest of temperate cereal crops on a world scale, it attacks all the major cereals and pasture grasses. The organic sector is in need of alternative aphicides or products that can repel this...

Pyrolysis is a well-known process for biomass upgrading and a great deal of works are available about it. However, they focus on conventional lignocellulosic samples and the information about any other less common samples, but still valuable, is very difficult to find. For instance, Brazilian ginseng (Pfaffia glomerata) is a feedstock without hemic...

The sugarcane sector in Brazil has undergone a major modernization in the last thirty years. Embracing the biorefinery concept, this sector is investigating bioproduct diversification and mostly putting a lot of effort and investment on second generation ethanol production. In this context, the investigation of the integration of a third generation...

Porous polymeric materials are studied in tissue engineering, because they can act as support for cell proliferation and as drug delivery vehicles for regeneration of tissues. Hydrogel foaming with supercritical CO2 is a suitable alternative for the creation of these structures, since it avoids the use of organic solvents and high temperature in th...

Quercetin is an antioxidant compound with highly promising pharmacological properties against a wide variety of diseases. A major limitation for the clinical application of quercetin is its low bioavailability, due to its low solubility in water. In this work, quercetin is microencapsulated in a surfactant material with the objective of increasing...

Holm oak (Quercus ilex) sapwood was submitted to a hydrothermal treatment and liquid fractions rich in hemicelluloses were obtained. The chemical composition as well as the molar mass were analysed during the experiments. The effect of temperature (130-170. °C) and reaction time (5-220. min) on the conversion and molar mass of the obtained hemicell...

Supercritical Fluid Extraction of Emulsions (SFEE) is a method used for producing aqueous suspensions, containing encapsulated particles in nanometric scale, through the extraction of an organic phase from an emulsion with supercritical CO2. Optimization of SFEE process conditions is complex as they influence several process steps. In this work, et...

Quercetin is an antioxidant compound with promising activity against a wide variety of diseases. However, a major limitation for the clinical application of quercetin is its low bioavailability, due to its low solubility in water. One way to increase the bioavailability of quercetin is to precipitate it in sub-micrometricscale, encapsulated by a su...

In the present study, the software Aspen Plus® was used to analyse two different systems for CO2 recycle in a SFE process for extraction of more polar compounds using ethanol as co-solvent, the most common co-solvent used due to its environment-friendly nature. The extraction process of β-ecdysone from Brazilian ginseng roots was considered as exam...

The supercritical water hydrolysis (SCWH) of biomass (P = 250 bara & T = 400 °C) allows directly obtaining sugars, which are high value products in the chemical industry, in reaction times lower than 0.2 s. The process is characterized by the high selectivity values which can be obtained controlling the reaction time. Reaction kinetics show that gl...

The efficiency of maltodextrin, whey protein isolate, and pea protein isolate to formulate a polyphenol-enriched grape marc extract by spray drying has been compared. Different inlet (120–140 °C ) and outlet (81–89 °C ) temperatures have been evaluated, as well as the amount of carrier expressed as carrier/extract ratio (0.1:1–1:1). The particles o...

A supercritical fluid is a gas that is pressurized and heated to a compressed fluid state, which is above both the critical pressure and the temperature. In this state, density and subsequently solvent strength and transport properties are highly adjustable by modest changes in temperature and pressure. Complex phase behavior and interactions with...

Microwave assisted extraction has been proved to be a useful tool for the recovery of valuable compounds from natural products. However, little is known about the dielectric properties for mixtures of natural products and solvents. In this work, a semi-empirical model is proposed to calculate the dielectric properties of these systems. The variable...

Development of effective green strategies and processes for the selective recovery of bioactive from winemaking waste streams.

A novel process coupling the fractionation and hydrolysis reactors is presented. Holm oak was used as real lignocellulosic biomass to be treated. In the fractionation reactor, hemicellulose and cellulose were solubilized and partially hydrolyzed in different stages with the aim of feeding the hydrolysis reactor with high C5 concentrations or C6 con...

Continuous hydrothermal synthesis was highlighted in a recent review as an enabling technology for the production of nanoparticles. In recent years, it has been shown to be a suitable reaction medium for the synthesis of a wide range of nanomaterials. Many single and complex nanomaterials such as metals, metal oxides, doped oxides, carbonates, sulf...

Epigallocatechin gallate (EGCG) is the catechin with higher antioxidant activity present in green tea. Nevertheless, due its low bioavailability, it is necessary the development of EGCG formulations capable of improving its stability resulting in increased bioavailability and thus higher biological activity of this catechin (e.g. antioxidant activi...

Supercritical anti-solvent (SAS) conditions to obtain the maximum enrichment of total polyphenols from grape marc extract was studied by 2³ factorial design. Operating at 12 MPa, 45 °C and 0.99 CO2 molar fraction, a relative enrichment of 350% of total polyphenols as well as a relative enrichment of proanthocyanidins fractions between 300 and 450%...

Recently, supercritical fluid extraction (SFE) has been indicated to be utilized as part of a biorefinery, rather than as a stand-alone technology, since besides extracting added value compounds selectively it has been shown to have a positive effect on the downstream processing of biomass. To this extent, this work evaluates economically the encou...

Quercetin is an antioxidant compound, and it is a highly promising material against a wide variety of diseases, including cancer. A major limitation for the clinical application of quercetin is its low bioavailability, due to its low solubility in water. One way to increase the bioavailability of quercetin is to precipitate it in sub-micrometric sc...

The aim of this work was to develop a user-friendly Excel interface to adjust the yields of an extraction column for SCF extraction. Moreover, this program could simulate the dynamic concentration profiles inside the column, being a useful teaching tool. The model comprises non-stationary mass balances for recovered compounds in both phases (solid...

Herbal medicinal plants are important sources of bioactive, medicinal compounds. In this work, impregnation of phytol as a model compound and multicomponent Clinacanthus nutans (C.nutans) plant extracts into alginate and silica aerogels was investigated, applying two different methods: wet impregnation and supercritical impregnation. Two types of C...

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This work is focused on the influence of CO2 in cellulose processing for substitution reactions. As a previous step melting point depression and the effect of viscosity reduction caused by solubilisation of CO2 were experimentally studied.

The hydrolytic hydrogenation of cellulose was studied using mesoporous Ru/MCM-48 as a catalyst. Supercritical water (SCW) was used as a reaction medium for cellulose hydrolysis, since in this reaction medium it is possible to depolymerize cellulose with a high selectivity towards sugars (70% w/w), avoiding degradation reactions when extremely low r...

Supercritical water has been demonstrated as a suitable reaction media for the generation of nanomaterials. Many single and complex metal oxides can be obtained using hydrothermal synthesis techniques. This work presents a methodology to characterise continuous hydrothermal flow systems both experimentally and numerically, working at low Reynolds n...

The formulation of natural substances using a biocompatible or biodegradable carrier material to form composites or encapsulates has great relevance for the pharmaceutical, cosmetic, and food industries. Several precipitation methods with supercritical fluids have been successfully adapted to produce these materials. Some of these processes are cur...

Grape marc polyphenols encapsulation in natural origin carriers by high pressure and supercritical fluid techniques

The effect of viscosity reduction caused by the solubilization of CO2 is studied in order to improve the biomass processing in ionic liquids. To do so, densities and viscosities of the pure ionic liquid 1-allyl-3-methylimidazolium chloride and its mixtures with CO2 up molar fractions of 0.25 and temperatures between 333 and 372 K have been experime...

A trickle bed reactor (TBR) was used to study different process parameters upon hydrogen peroxide direct synthesis. The catalysts used were commercial palladium on active carbon. The influence of pressure (1.75-25 barg), temperature (5-60°C), liquid flow rate (2-13.8 ml·min⁻¹), gas flow rate (3.4-58.5 ml·min⁻¹), catalyst amount (90-540 mg), Pd perc...

The purpose of this work was to study the behavior of (1-3)(1-4)- β -D-glucan in pressurized hot water. For this purpose, solid β -glucan (450 kDa) was put in water and heated at different temperatures (120, 150, and 170°C) for different times (5 to 360 minutes). At 120°C it was found that the highest soluble β -glucan concentration was measured af...

(1,3)-(1,6)-B-d-Glucans were extracted from Ganoderma lucidum (34.2%, w/w) using pressurized hot water as solvent (P = 5 MPa) in a fixed bed laboratory scale unit. A RSM Box–Behnken experimental design was used to evaluate the effect of the temperature (135–175ªC), flowrate (0.7–1.3 mL/min) and solvent to biomass ratio (20–60 mL/g) on the extractio...