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The kinetics of the supercritical fluid extraction of edible and discarded chia seeds was studied and modelled for the first time. The total oil was removed at 45 MPa and 60 °C after 240 min. The extraction kinetics was simulated using a dynamic model in gPROMS ModelBuilder environment and the kinetic parameters estimated. Triolein was chosen as a model compound of the chia oil. The agreement between the experimental yields and those calculated by the model was good with deviations in the range (1.2–6.6) %, except at 25 MPa and 60 °C (AARD = 9.5%)., J. A. P. Coelho, R. M. Filipe and R. P. Stateva acknowledge the funding received from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 778168. J. A. P. Coelho, and R. M. Filipe acknowledge the funding received from Fundação para a Ciência e a Tecnologia, Portugal, under projects UID/ECI/04028/2013 and UID/QUI/00100/2013. Chia seeds were generously supplied by PRIMARIA (www.primaria.biz).

Although triacylglycerols (TAG) are the major constituents of chia oil, it also contains minor lipid fractions that include phospholipids (PL) among other desirable components. Its amphiphilic character and excellent biocompatibility make PL appropriate for numerous applications with technological and nutritional significanceand potential health benefits. Given the difficulties entailed by the PL isolation, the efficiency for extracting such compounds using two environmental friendly techniques, pressurized liquid extraction (PLE) and supercritical fluid extraction (SFE) was evaluated. By using PLE with food-grade ethanol (EtOH), an oil recovery close to 100% was achieved in just 10 min. This oil extract was particularly rich in α-linolenic acid (ALA; 70%) as compared to the oil extracted by SFE (56%). In the case of SFE, the oil recovery was only 87% but increased to 99% when ethanol was added to CO2. However the use of co-solvent did not affect the fatty acid profile of the supercritical extracts or their TAG composition, where the high molecular weight TAG species were the predominant in all cases. With the exception of SFE without co-solvent, all methods applied were capable of extracting the PL fraction, although the content and distribution of the individual components present in this fraction differed markedly depending on the extraction conditions used. In this context, the use of a sequential extraction process, combining SFE and PLE was particularly interesting. The re-extraction by PLE of the chia cake, previously defatted by SFE, allowed to obtain an oil extract highly enriched in PLs, whose content exceeded 16% and with a higher PL species than the rest of the oil extracts., This study was supported in part by grants from the Spanish Ministry of Science, Innovation and Universities, Spain (AGL2017-87884 MINECO/AEI/FEDER, UE); by the Comunidad de Madrid through the B Programa de Actividades en Tecnologías, Spain (ALIBIRD-CM S2013/ABI-2728).

Supercritical anti-solvent precipitation (SAS) using carbon dioxide is a novel technique that can be used to produce powdered ingredients in small size particles, facilitating their incorporation into food matrices. In this work, the SAS precipitation of a licorice root ethanolic extract was studied. SAS assays were carried out at 15–20 MPa, 308.15 and 313.15 K, and two different concentrations (9.6 and 14.2 mg/ml) of the ethanolic licorice extract. In the range of conditions investigated, SAS pressure and temperature did not affect significantly the precipitation yield, but phytochemicals recovery was higher with the lower licorice extract concentration. Moreover, the fractionation of licorice bioactives (liquiritin, liquiritigenin, isoliquiritigenin, glabridin and glycyrrhizic acid) was assessed, together with the content of total phenolic compounds and antioxidant activity of the powders and oleoresin by-products obtained. In this respect, precipitates and oleoresins presented significant differences in the concentration of some licorice bioactives, and higher antioxidant activity was observed in precipitates. Additionally, significant effect of pressure, temperature and licorice extract concentration on the morphology and particle size of precipitates was observed, recovering smaller and more regular particles at 15–20 MPa, 313.15 K and 9.6 mg/ml licorice extract concentration, attaining satisfactory yield and antioxidant activity., The authors gratefully acknowledge the financial support from Ministerio de Economía y Competitividad of Spain (Projects AGL2017-89055-R and AGL2016-76736-C3-1-R). Somaris E. Quintana is grateful for the funding provided by Gobernación de Bolivar and Fundación Ceiba, Colombia, in the project “Bolívar Gana con Ciencia”.

Background: Vaccinium meridionale Swartz (mortino) constitutes a source of bioactive phytochemicals, but reports related to its efficient and green production are scarce. In this study, pressurized liquid extraction (PLE) and ultrasound-assisted extraction of mortino were compared. Total phenolic content (TPC) and antioxidant capacity (ABTS•+ ) were determined. Beef burgers with 20 g kg-1 of mortino (MM) or its PLE extract (ME) were manufactured. Lipid oxidation (TBARS) and instrumental color changes were measured after refrigerated storage.; Results: High TPC (up to 72 g gallic acid equivalent kg-1 extract) was determined in mortino extracts, which was positively correlated with antioxidant activity. TBARS values of beef burgers containing either MM or ME did not change after refrigerated storage, whereas lipid oxidation of control burgers increased significantly. The color of burgers with added MM or ME was different (lower b* and a* values) from that of control burgers. However, the evolution of color after storage was similar between control and ME samples.; Conclusion: Mortino extracts with high TPC can be obtained by PLE. Both mortino and its PLE extract are able to control lipid oxidation of beef burgers, but the extract is preferred from the color quality point of view. © 2017 Society of Chemical Industry.; © 2017 Society of Chemical Industry.

The digestion, absorption, uptake and bioavailability of a rosemary supercritical fluid extract encapsulated in oil in water emulsion were studied. Two emulsions with opposite surface charge were prepared, containing 7% canola oil, and either 2% lactoferrin or whey protein isolate. When absorption and uptake of carnosic acid and carnosol were followed on Caco-2 cell monolayers, there were no differences with protein type. However, when co-cultures of HT-29 MTX were employed, the presence of mucus caused a higher retention of carnosic acid in the apical layer for lactoferrin emulsions. The immune activity of the bioavailable fractions collected from cell absorption experiments was tested ex vivo on murine splenocytes. Although transport through the intestinal barrier models was low, the bioavailable fractions showed a significant effect on splenocytes proliferation. These results demonstrated the potential of using rosemary supercritical extract through protein stabilized oil in water emulsions, as a food with immunomodulatory functionality., This work was partly funded by the Natural Sciences and Engineering Council of Canada, through the Canada Research Chair program and the Spanish Ministry of Economy and Competitiveness (FORCANCER project, AGL2013- 48943-C2-1-R). EA work was supported by the Alfonso Martin Escudero Foundation, through a Post-Doctoral Fellowship.

Licorice (Glycyrrhiza glabra L.) is a plant used widely in herbal medicines due to their several biological potentials. The supercritical extraction of licorice roots was investigated to assess the antioxidant and antimicrobial activity of the extracts. Extraction conditions were pressures from 15 to 40 MPa, 313.15 and 333.15 K, and ethanol cosolvent in the range of 0 to 20% mass. In the case of high-pressure extractions using pure carbon dioxide (CO2) fractionation of the supercritical extract was accomplished in a two-cell decompression system. Fractionation was carried out with the aim to examine the potential separation of the antioxidant and antimicrobial licorice compounds and thus increase the bioactive properties of the fractions obtained in each separation cell. Main licorice bioactive compounds, liquiritin, liquiritigenin, glycyrrhizin, isoliquiritigenin and glabridin, were identified by HPLC and quantified using standards. Extracts obtained with supercritical CO2 and ethanol cosolvent contain the higher amounts of phenolic compounds and also the higher antioxidant activity but exhibit low or even no antimicrobial activity. Using pure CO2 at high pressure coupled with the on-line fractionation of the extract, two samples were obtained which showed, respectively, lower phenolic compounds content and good antimicrobial capacity (first fraction) and higher phenolic compounds content and antioxidant capacity (second fraction). Thus, the advantages of supercritical on-line fractionation are demonstrated in the extraction of Licorice roots., The authors gratefully acknowledge the financial support from Ministerio de Economía y Competitividad of Spain (Projects AGL2016-76736-C3-1-R and AGL2015-64522-C2-R). Somaris E. Quintana is grateful for the funding provided by Gobernación de Bolivar and Fundación Ceiba, Colombia.

Achillea millefolium L. is a plant widely used in traditional medicine. Nowadays, there is a growing concern about the study of its bioactive properties in order to develop food and nutraceutical formulations. Supercritical anti-solvent fractionation (SAF) of an A. millefollium extract was carried out to improve its antioxidant and anti-inflammatory activities. A selective precipitation of phenolic compounds was achieved in the precipitation vessel fractions, which presented an antioxidant activity twice than original extract, especially when fractionation was carried out at 10 MPa. The main phenolic components identified in this fraction were luteolin-7-O-glucoside, 3,5-dicaffeoylquinic acid, 6-hidroxyluteolin-7-O-glucoside and apigenin-7-O-glucoside. However, separator fractions presented higher anti-inflammatory activity than precipitation vessel ones, particularly at 15 MPa. This fact could be related to separator fractions enrichment in anti-inflammatory compounds, mainly camphor, artemisia ketone and borneol. Therefore, SAF produced a concentration of antioxidant and anti-inflammatory compounds that could be used as high-added valued ingredients., This work was supported by Spanish Government (FORCHRONIC Project: AGL-2016-76736-C3-1-R) and Comunidad Autónoma de Madrid (ALIBIRD, project: P2013/ALI2728).

The simultaneous fractionation and precipitation of an ethanolic extract of rosemary (Rosmarinus officinalis L.) using supercritical carbon dioxide anti-solvent technique was studied, with the target of separate in two different fractions the key antioxidants of rosemary (i.e. rosmarinic acid, carnosic acid and carnosol). The effect of pressure and temperature on the fractionation process was investigated, together with the morphology and particle size distribution of the precipitates. Additionally, the chemical composition of the oleoresins were analyzed and reported. In the range of pressures (9–20 MPa) and temperatures (313–333 K) used in this work, the precipitates presented a 2–3 fold enrichment of rosmarinic acid, while carnosic acid and carnosol were concentrated (2–3 fold enrichment) in the oleoresin fractions. Furthermore, in general, oleoresins presented higher antioxidant activity than precipitates. Particles produced with a nozzle of diameter 101.6 μm were smaller and more spherical with increasing pressure (mean value 4–10 μm at 20 MPa) and decreasing temperature., The authors gratefully acknowledge the financial support from Ministerio de Economía y Competitividad of Spain (Proyect AGL2016-76736-C3-1-R). Somaris E. Quintana is grateful for the funding provided by Gobernación de Bolivar and Fundación Ceiba, Colombia, in the project “Bolívar Gana con Ciencia”.

This article belongs to the Special Issue Advances in Supercritical Fluid Food Science and Technology., Heather (Calluna vulgaris L.) and marigold (Calendula officinalis L.) are two rich sources of bioactive pentacyclic triterpenes. The supercritical carbon dioxide (SCCO2) extraction of these two plants was explored at a pressure range of 25–50 MPa, 50 °C, with or without fractionation, different extraction times (1.5–4.0 h) and using ethanol as a co-solvent (0 and 10% w/w). In order to determine potential synergisms, a combined extraction (heather + marigold 50:50) was also studied. In general, higher extraction yields were achieved when the co-solvent was added. Higher concentrations of total triterpenic acids were obtained in heather extracts, specially using ethanol. The co-solvent did not increase the terpene concentration in marigold extracts. For the combined extraction, an antagonist effect in the triterpene concentration was observed in absence of a co-solvent, whereas a synergistic effect was exhibited in its presence, especially for ursolic acid. In general, the extracts showed a certain anti-inflammatory effect, although a straight correlation with the analyzed triterpenic acids concentration was not exhibited. Moreover, the combined extraction exposed a similar anti-inflammatory activity in comparison with the individual plant extracts., The authors gratefully acknowledge the financial support from Ministerio de Economía y Competitividad of Spain (project AGL2013-48943-C2) and the Comunidad Autónoma de Madrid (ALIBIRD, project number S2013/ABI-2728).

Chia seeds constitute a promising source of α-linolenic acid (ALA). In the present work, an underutilized and cheaper set of chia seeds, which were discarded after the harvest according to quality criteria - named in this work as low oil content seeds (LOCS) - have been evaluated as a potential source for obtaining PUFA-enriched oils against the commonly studied high-quality chia seeds denoted as high oil content seeds (HOCS) in this study. Two efficient and environmental friendly techniques, supercritical fluid extraction (SFE) and pressurized liquid extraction (PLE), were evaluated to optimize the extraction process of chia oil. At 60 °C, by using pressurized food-grade ethanol, recoveries close to 100% were achieved from both sets of seeds in a short extraction time (10 min). By using SFE, the greatest oil extraction yield (>95%) was attained at the highest pressure and temperature conditions (45 MPa and 60 °C) after 240 min. At the early stage of SFE extraction, both LOCS and HOCS exhibited a similar kinetic behavior, reaching oil extraction rates of 0.59 g oil/min and 0.64 g oil/min, respectively. No differences were found between the fatty acid profile of the oils extracted from LOCS and HOCS both by PLE and SFE. ALA and linoleic acid (LA) concentrations ranged between 65‐68% and 17–23% respectively, and a predominance of high molecular weight triglycerides (≥ CN50), was found in all extracted oils. In conclusion, LOCS might constitute a new suitable raw material for the production of ALA-enriched oils. Concerning the extraction methods assayed, the oil was almost entirely recovered by both PLE and SFE at the used conditions., This study was supported in part by grants from the Spanish Ministerio de Economía y Competitividad (AGL2014-56464) and by the Comunidad de Madrid through the B Programa de actividades en tecnologías (ALIBIRD-CM S2013/ABI-2728).

This paper reports experimental data to analyze the effect of different green cosolvents, namely ethyl lactate, ethyl acetate and ethanol, on the supercritical carbon dioxide (SCCO) extraction of caffeine from green tea leaves. The experiments were carried out in a pilot-scale plant using two different approaches: a static procedure in which the cosolvent was introduced in the extraction cell soaking the vegetal material and then SCCO was pumped, and a dynamic assay in which the cosolvent was pumped and mixed with SCCO before introduction into the extraction cell. The overall caffeine recovery from plant matrix was determined for all experiments at the same extraction conditions (30 MPa and 343 K). Additionally, the overall extraction curves of the static experiments were determined at the same process conditions, and the mass transfer model of Sovová was utilized to adjust the kinetic data and to determine the mass transfer coefficients. The highest caffeine yield was obtained with ethyl lactate in both static and dynamic extractions (13.0 and 14.2 mg/g of tea, respectively), followed by ethanol (10.8 mg/g with the static method and 8.8 mg/g with the dynamic method). The yield obtained with ethyl acetate in both extraction approaches was lower than 7 mg/g. These data reinforce previous results obtained by the authors regarding the competence of ethyl lactate in the extraction of caffeine from natural materials., D. Villanueva acknowledges the predoctoral contract (JAE) given by the Consejo Superior de Investigaciones Científicas (CSIC) of Spain. This work was financed thanks ALIBIRD, S2013/ABI-2728 (Comunidad de Madrid) project.

Trabajo presentado a la III Iberoamerican Conference on Supercritical Fluids celebrada en Cartagena de Indias (Colombia) del 1 al 5 de abril de 2013.

The extraction of marigold (Calendula officinalis) oleoresin with supercritical carbon dioxide SCCO2 was carried out in a small scale extraction vessel (2.7 × 10−4 m3) studying different extraction pressures (14, 24 and 34 MPa) and different flow rates (15, 30 and 45 g min−1) at 313 K. Then, using semi-empirical engineering scaling criteria (constant solvent lineal velocity or constant solvent residence time) and the Broken and Intact Cell (BIC) model, the scaling up to larger extraction vessels (1.35 × 10−3 m3 and 5.16 × 10−3 m3) was theoretically investigated. According to the BIC model, by keeping constant the CO2 residence time in the different size vessels a good reproduction of the kinetic behavior should be obtained. Nevertheless, experimental results did not confirm model predictions, and in fact none of the scaling criteria studied resulted adequate in the marigold supercritical extraction scaling up. Thus, using all the experimental overall extraction curves obtained, a new specific correlation was developed between the Schmidt number (Sc), CO2 mass flow, bed geometry and the supercritical mass transfer coefficients kYA with a good fit (R2 = 0.9767) for scaling up the supercritical extraction of marigold., López-Padilla A thanks to Administrative Department of Science, Technology and Innovation − Colciencias (Call 568/2012) for his Ph.D. fellowship. This work was financed thanks to ALIBIRD project: S2013/ABI-2728 (Comunidad de Madrid).

Achillea millefolium L. (yarrow) from Bulgaria was extracted in a supercritical pilot-scale plant using carbon dioxide (CO). First, the extraction yield was studied as a function of time at 14 MPa, 40 °C and 70 g/min of CO. Then, the extraction time was set in order to study the effect of different process parameters (pressure, temperature, CO flow and use of ethanol as co-solvent) on the extraction yield. The composition of the volatile oil obtained in yarrow extracts was thoroughly studied by GC–MS. Overall extraction yield increased with pressure, temperature and amount of co-solvent. Nevertheless, minor effect of the studied process parameters on yarrow volatile oil profile was found. On the other hand, important differences were found when comparing the volatile oil composition of Bulgarian Achillea millefolium L. extracts with those obtained from other origins., The authors gratefully acknowledge the financial support from Ministerio de Economía y Competitividad of Spain (project AGL2013-48943-C2) and the Comunidad Autónoma de Madrid (ALIBIRD, project number S2013/ABI-2728).

This is the accepted version of the following article: Journal of the Science of Food and Agriculture 94 (2014), which has been published in final form at http://dx.doi.org/10.1002/jsfa.6788

The solubility of ferulic acid in ethyl lactate + water mixtures was measured at ambient temperature and pressure, and reported for the first time in this work. It was demonstrated that the acid solubility in the respective mixed solvents was considerably higher than in either pure ethyl lactate or water. Similar behavior pattern was recently reported by the authors for the solubility of caffeine in ethyl lactate + water mixtures. UNIQUAC and modified UNIFAC (Dortmund) were applied to represent the solubility of ferulic acid and caffeine in the mixed solvents and their capabilities to describe adequately the cosolvent effect observed was tested and compared. The results obtained demonstrated that the UNIQUAC model provided excellent correlation of the experimental data for both systems. The UNIFAC model, on the other hand, was applied in a completely predictive manner and produced very good results for ferulic acid solubility and just qualitative predictions for caffeine., D. Villanueva acknowledges the predoctoral contract (JAE) given by the Consejo Superior de Investigaciones Científicas (CSIC) of Spain. This work was financed thanks ALIBIRD, S2013/ABI-2728 (Comunidad de Madrid) project.

Supercritical fluid extraction (SFE) is an innovative, clean and environmental friendly technology with particular interest for the extraction of essential oil from plants and herbs. Supercritical CO 2 is selective, there is no associated waste treatment of a toxic solvent, and extraction times are moderate. Further, supercritical extracts were often recognized of superior quality when compared with those produced by hydro-distillation or liquid-solid extraction. This review provides a comprehensive and updated discussion of the developments and applications of SFE in the isolation of essential oils from plant matrices. SFE is normally performed with pure CO 2 or using a cosolvent; fractionation of the extract is commonly accomplished in order to isolate the volatile oil compounds from other co-extracted substances. In this review the effect of pressure, temperature and cosolvent on the extraction and fractionation procedure is discussed. Additionally, a comparison of the extraction yield and composition of the essential oil of several plants and herbs from Lamiaceae family, namely oregano, sage, thyme, rosemary, basil, marjoram and marigold, which were produced in our supercritical pilot-plant device, is presented and discussed. © 2012 Elsevier B.V., This work has been supported by project AGL2010-21565 (subprogram ALI) and project INNSAMED IPT-300000-2010-34 (subprogram INNPACTO) from Ministerio de Ciencia e Innovación (Spain) and Comunidad Autónoma de Madrid (project ALIBIRD-S2009/AGR-1469).

Production of prebiotic carbohydrates at competitive prices is a challenge nowadays since the well-established production processes involve many purification steps which are labour intensive and require important amounts of reagents and products thus increasing prebiotic's price. Several processes have been studied in our laboratory involving the use of Supercritical Fluid Technology to fractionate and purify carbohydrate solid mixtures. Research carried out at laboratory scale using theoretical mixtures (lactose/lactulose and galactose/tagatose), commercially available carbohydrate mixtures and carbohydrate mixtures produced by enzymatic transglycosylation and isomerized with complexating reagents demonstrated that purification of prebiotic carbohydrates was technically possible by supercritical fluid extraction. In the present work, the process optimized at laboratory scale to fractionate carbohydrate mixtures produced by enzymatic transglycosylation has been scaled-up to an industrial level and its economic feasibility has been simulated employing AspenONE ® V7.3 software to obtain consistent data supporting the interest of a potential investment for prebiotics production at large scale using supercritical fluids. © 2012 Elsevier B.V., This work has been financed by CSD2007-00063 FUN-CFOOD (Programa CONSOLIDER-INGENIO 2010) and Project ALIBIRD S2009/AGR-1469 (Community of Madrid) projects. F.M. thanks MEC and FECyT for a postdoctoral fellowship.

In this paper, the potential application of non-toxic agrochemical solvent—ethyl lactate, to recover α-tocopherol from olive oil is studied. The work is based on experimental and modeling studies of the liquid–liquid equilibria at ambient pressure of three model systems: (i) binary (olive oil + ethyl lactate), (ii) pseudo-binary (ethyl lactate + (olive oil containing 11.60 mass% of oleic acid)), (iii) ((ethyl lactate containing 2.80% of water) + olive oil), and (iv) ternary (α-tocopherol + olive oil + ethyl lactate). The favorable separation factors obtained reveal the strength and potential of ethyl lactate as a green solvent for the recovery.

Supercritical fluid chromatography (SFC) was employed to fractionate thyme (Thymus vulgaris L.) extracts, which were obtained by supercritical carbon dioxide extraction of thyme leaves. First, different supercritical extracts were produced at 313 K and at different pressures (15, 30 and 40 MPa). Thymol, a monocyclic terpenoid with recognized antiseptic, analgesic and anti-inflammatory properties, was identified and quantified in the different samples by GC-MS. Then, the supercritical extracts were fractionated by semi-preparative SFC, and different conditions such as pressure, temperature and amount of cosolvent (ethanol) employed were studied. Around a two fold increase of thymol was achieved at 15 MPa, 50 °C and 3% ethanol cosolvent, recovering 97% of the monocyclic terpenoid extracted. © 2010 Elsevier B.V. All rights reserved., The authors gratefully acknowledge the financial support from the Ministerio de Ciencia e Innovación (project 25506 FUN-C-FOOD) and Comunidad Autónoma de Madrid (ALIBIRD, project S-505/AGR-0153).

Enzymatic esterification and supercritical fluid extraction was used to produce phytosterol esters from soybean oil deodorizer distillates. The raw material was first subjected to a two-step enzymatic reaction; the product obtained mainly comprised fatty acid ethyl esters, tocopherols and phytosterol esters, together with minor amounts of squalene, free fatty acids, free sterols and triacylglycerols. The phytosterol esters were then purified from this mixture using supercritical carbon dioxide. Experimental extractions were carried out in an isothermal countercurrent column (without reflux), with pressures ranging from 200 to 280 bar, temperatures of 45-55 °C and solvent-to-feed ratios from 15 to 35 kg/kg. Using these extraction conditions, the fatty acid esters were completely extracted and, thus, the fractionation of tocopherols and phytosterol esters was studied. At 250 bar, 55 °C and a solvent-to-feed ratio of 35, the phytosterol esters were concentrated in the raffinate up to 82.4 wt-% with satisfactory yield (72%).

Supercritical carbon dioxide extraction to separate phytosterol esters from fatty acid esters and tocopherols was simulated and optimized using the group contribution equation of state. Experimental extraction data at 328 K, pressures ranging from 200 to 280 bar and solvent-to-feed ratio around 25, was employed to verify the performance of the thermodynamic model. The raw material is the product obtained after a two-step enzymatic reaction carried out on soybean oil deodorizer distillates, and contains mainly fatty-acid ethyl esters, tocopherols and phytosterol esters. The extraction process was simulated using model substances to represent the complex multicomponent feed material. Nonlinear programming techniques were applied to find out optimal process conditions for a steady-state countercurrent process with partial reflux of the extract. The process optimization procedure predicts that a product with 94.2 wt % of phytosterol ester purity and 80% yield could be achieved. © 2009 American Institute of Chemical Engineers AIChE J, 2009

Supercritical carbon dioxide was used as an extractive solvent to remove free fatty acids from cold-pressed 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.

Carbon dioxide can act as an expanding medium to carry out enzymatic reactions. Particularly, by dissolving CO2 in mixtures comprising lipid-type substances and simultaneously increasing the pressure, the miscibility among reactants is enhanced, viscosity of the reaction mixture decreases, and diffusion of reactants and products is improved. Knowledge about the phase equilibrium behavior of the reactive mixture + CO2 allows an adequate selection of conditions to achieve the homogeneous phase during reaction. In this work, phase equilibria data of the pseudoternary system sunflower oil + ethanol + CO2 at two different conditions (313 K and 13 MPa; 333 K and 20 MPa) were investigated to provide an understanding of the phase behavior of vegetable oil ethanolysis reactions in CO2-expanded media. Measurements were carried out by the analytical static method, using a variable-volume view cell equipped with a cold end light and a magnetic stirrer. Experimental tie-lines were determined for both types of equilibr...

Nowadays consumers hold high standards for the foods they consume and they also demand for products that can provide added healthful benefits; two of these products with an observed prebiotic activity, tagatose and lactulose, are the core of our study. These two carbohydrates are ketoses and have important biological activities, such as the stimulation of the growth of beneficial microorganisms in the colon. They are currently produced by alkaline isomerization of the corresponding aldose, followed by several purification steps to remove carbohydrate by-products and the unreacted aldose (around 30%). In this work, the possibility of using supercritical fluid extraction (SFE) technology to fractionate complex carbohydrate mixtures is analyzed. The study is based on previous results obtained for the fractionation of solid binary carbohydrate mixtures such as lactulose–lactose and tagatose–galactose. The appropriate selection of the co-solvent employed, together with the most suitable extraction conditions (including temperature, pressure and co-solvent flow rate) allows the selective extraction of the prebiotic ketose with high selectivity and recovery. The fractionation by SFE of a complex commercial carbohydrate mixture, containing around 74 wt.% of lactulose and 24 wt.% of different aldose carbohydrates, was carried out at the optimal extraction conditions attained in the study of binary mixtures. The selective extraction of the ketosugar lactulose was also observed in this case, obtaining an extract with 81 wt.% lactulose and around 67% yield.

This work presents the main results attained by our research group merging chemical reaction, supercritical fluid extraction, thermodynamic phase equilibrium modeling and chemical analysis to study alternative supercritical extraction processes related with oil-type materials. Different fatty oil raw materials were fractionated in a countercurrent packed column using supercritical carbon dioxide and following different process targets, such as the deacidification of lampante olive oil and the recovery of minor lipid compounds (squalene, tocopherols and phytosterols) from industrial byproducts and wastes. If necessary, in order to facilitate the concentration of the preferred minor lipids in the raffinate product, the raw material employed was previously esterified. The GC-EoS model was used as the thermodynamic tool to represent phase equilibria behavior of the multicomponent oil-type material + CO2 mixture, and was employed to guide experiments so as to simulate and optimize the supercritical extraction processes. The coupling of thermodynamic modeling with experimental work has offered an efficient low-time consuming tool to analyze the viability of supercritical extraction processes.

Ethanolysis of a raffinate product-obtained after distillation of olive oil-catalyzed by three commercial lipases (from Candida antarctica, Rhizomucor miehei and Thermomyces lanuginosa) was studied. Uni-response model derived from a generalized Michaelis–Menten mechanism was utilized to describe the rates of formation of ethyl esters from the fatty acids present in the precursor oil. The rate constants for the ethanolysis of triacylglycerols and steryl esters under the reaction conditions were compared. Moreover, inactivation of three lipases was evaluated. Because the half-life of the enzyme is comparable to or even shorter than the half-life of the reaction, the intrinsic reaction rate and enzyme deactivation must both be considered in modeling the kinetics.

The purification of squalene from residues of the olive oil deodorization process using countercurrent supercritical carbon dioxide extraction was studied. The raw material employed is a by-product obtained after distillation and ethylation of olive oil deodorizer distillates. This by-product contains mainly squalene and fatty acid esters. The Group Contribution Equation of State was employed to simulate the separation process and to design the experimental extractions, which were carried out in an isothermal countercurrent column, without reflux, at 343 K, pressures ranging from 150 to 230 bar and a solvent-to-feed ratio around 13. Satisfactory agreement was found between experimental and calculated yields and phase compositions, obtaining a raffinate product with a squalene concentration up to 90 wt.%. Finally, the thermodynamic model was employed to find out optimal process conditions to enhance squalene recovery, including partial reflux of the extract product and recirculation of the supercritical solvent in a continuous countercurrent extraction column.

Solubility of six different carbohydrates in methanol, ethanol, 1-propanol, and 2-propanol were measured at 22, 30, and 40°C. Ketose sugars (fructose, tagatose, and lactulose) show higher solubilities than aldoses (glucose, galactose, and lactose). The binary solid–liquid equilibrium data obtained was satisfactory represented by using the A-UNIFAC model. Additionally, the capability of the model to predict the carbohydrate solubility in alcohol–alcohol and alcohol–water mixed solvents was explored. © 2007 American Institute of Chemical Engineers AIChE J, 2007

Ethyl-lactate (ethyl 2-hydroxy-propanoate) is a bio-renewable agrochemical solvent, very suitable and environmental benign for food applications, permitted by the U.S. Food and Drug Administration as pharmaceutical and food additive. In previous work, the authors demonstrated that pressurized liquid extraction (PLE) using ethyl lactate is a suitable alternative to remove caffeine from vegetal materials, e.g. green coffee beans and green tea leaves. The solubility of caffeine in ethyl lactate + water mixtures, at ambient temperature and pressure, exhibits a substantial increase for 60:40% ethyl lactate + water mixtures (data reported in this work). This result motivated the analysis of the effect of the ethyl lactate + water mixtures for the decaffeination target. Furthermore, in the case of green tea, the removal of caffeine reducing the extraction of catechins is desirable due to the adverse effects of caffeine on health, while catechins are high valued functional food ingredients. Thus, the use of ethyl lactate, water and ethyl lactate + water mixtures to attain this objective, i.e. the removal of caffeine form green tea leaves minimizing the extraction of catechins, was studied in this work. PLE was carried out in the temperature range 373-473 K and using different ethyl lactate + water mixtures. Extraction yield and recovery of key bioactive compounds (caffeine and monomeric catechins) were determined and compared, and the caffeine/catechins selectivity of the different solvents employed was estimated. High extraction yields were obtained with a mixture containing 25:75% of ethyl lactate + water, with values around 1.5 and 3.5 times higher than, respectively, the yields obtained with water and ethyl lactate. Yet, pure ethyl lactate proved to be the most selective solvent to extract caffeine from green tea leaves, minimizing the co-extraction of catechins, with a caffeine/catechins selectivity of 2.8 to 5.5 in the range 373-423 K. At these temperatures, with short extraction times (20 min) the recovery of caffeine is in the range 53-76% but only 26-36% of catechins present in the tea leaves were removed., D. Villanueva acknowledges the predoctoral contract (JAE) given by the Consejo Superior de Investigaciones Científicas (CSIC) of Spain. This work was financed thanks to AGL2011-29857-C03-01 (Ministerio de Economía y Competitividad) and ALIBIRD, S2013/ABI-2728 (Comunidad de Madrid) projects.

Rosmarinus officinalis L. is an aromatic plant with components known to confer health-promoting properties. The present study aimed to enhance the bioavailability of the main compounds, carnosic acid and carnosol, by encapsulation. The rosemary extracts were obtained by supercritical fluid extraction, and then different delivery systems were tested, namely oil emulsion droplets and casein micelles, native protein particles present in milk. Soybean oil in water emulsions and casein dispersions were digested in vitro with simulated gastric and intestinal fluids, and the bioavailability of the extract was tested on Caco-2 cell monolayers. The apical and basolateral compartments and the cell lysates were further analyzed for carnosic acid and carnosol content by means of ultra-performance liquid chromatography-tandem mass spectrometry (UPLC/MS/MS). The encapsulation in both casein micelles and emulsion droplets significantly protected the rosemary extract from degradation during digestion, resulting in 81 and 97 % recovery of carnosic acid, respectively. This high protection rate prompted an increased bioavailability of carnosic acid and carnosol in Caco-2 monolayers, with up to 10 % carnosic acid recovered in the bioavailable fraction. Encapsulation in delivery systems like casein micelles or emulsion droplets opens new possibilities for successful incorporation of rosemary extracts in healthy food formulations with increased functionality., This project was partly funded by the Spanish Ministry of Science and Innovation (CICYT) (project: IPT-300000-2010-034), Ingredientes Saludables Mediterráneos Innovadores (INNSAMED), Comunidad Autónoma de Madrid (ALIBIRD, project S-505/AGR-0153), and the Natural Sciences and Engineering Council of Canada (NSERC). Authors are members of the COST Infogest program, and the funding for the Short-Term Scientific Mission (STSM) of E. Arranz is acknowledged.

This paper reports a method to produce a solvent-free extract from green tea leaves with high content of catechins and low content of caffeine, in two steps and using only “green” solvents. The method is based on the pressurized liquid extraction (PLE) of the green tea leaves using ethyl lactate as solvent, followed by a selective precipitation procedure using the supercritical carbon dioxide (SCCO2) antisolvent (SAS) technique. PLE was accomplished at 100 °C and 10 MPa, on the basis of a previous work. The influence of pressure (15–30 MPa) and temperature (50 °C and 70 °C) on the SAS precipitation process was experimentally studied in terms of precipitation yield, concentration of key bioactive compounds (caffeine and monomeric catechins) and total content of phenols of the precipitates. Additionally, a comparison using a different organic solvent (ethanol) for the extraction and precipitation steps is reported. The precipitates obtained from the ethyl lactate PLE extracts were decaffeinated (giving less than 1% mass caffeine in the dry matter) and the concentration of catechins was close to 23% mass. The total phenolic content of the precipitates was up to 590 mg of gallic acid equivalents per g of precipitate, which represents an increase of up to 25% with respect to the PLE extracts., D. Villanueva acknowledges the predoctoral contract (JAE) given by the Consejo Superior de Investigaciones Científicas (CSIC) and the fellowship given by Universidad Autónoma de Madrid. This work was financed thanks to Comunidad Autónoma de Madrid (project ALIBIRD-S2013/ABI-2728). Turner acknowledges the Swedish Research Council (2010-333) and the Swedish Research Council Formas (229-2009-1527). Irene Rodríguez Meizoso acknowledges The Swedish Research Council (VR, 2012-4124) for financial support.

The recovery of minor lipid compounds (tocopherols and phytosterols) from sunflower oil deodorizer distillates using countercurrent supercritical carbon dioxide extraction has been studied. Since the raw material employed contains large amounts of triacylglycerols and free fatty acids, chemical transformation of these compounds into their corresponding fatty acid ethyl esters was previously carried out, in order to favor the concentration of minor lipids in the raffinate product. Extractions of the original and pretreated raw material were carried out in a pilot-scale plant at 65 °C, with pressures ranging from 15 to 23 MPa and solvent-to-feed ratios from 15 to 30. The influence of the feed composition in the extraction process was analyzed by comparison of the tocopherol and phytosterol yields and enrichment factors obtained in each case. The chemical transformation of the deodorizer distillate composition significantly enhances the concentration of minor lipids in the raffinate product. Additionally, the reaction step produced a solid phase, mainly consisting of sterols, which was isolated from the liquid product.

Specially designed chromatographic columns were evaluated for antioxidant compounds separation by supercritical fluid chromatography (SFC) with pure CO2. Columns studied involved the use of commercial octadecylsilica particles (ODS) and silica particles coated with a stationary phase commonly used in gas chromatography, such as CW20M (polyethylene glycol) of high polarity. In order to select the appropriate chromatographic conditions to elute antioxidant compounds of phenolic structure, carnosic acid was selected as a model molecule and a theoretical study of the solubility of carnosic acid was performed. Carnosic acid was eluted using CO2 as mobile phase (without modifiers) with a pressure programming up to 37 MPa (and at different temperatures) but only when coated particles were used. No elution was possible when ODS particles were tested, probably due to the strong interactions of the acid group of the molecule with the active sites remaining in the column. A separation of a complex mixture of a rosemary antioxidant extract (obtained by supercritical fluid extraction) using the columns designed in the present work is shown.

Betulinic acid (3β, hydroxy-lup-20(29)-en-28-oic acid) is a bioactive triterpenic acid which was identified in various botanical sources and in considerable amounts in the bark of plane tree (Platanus acerifolia L.). In this work, the recovery of betulinic acid from plane tree bark was studied using different liquid solvent based extraction methods, namely solid-liquid extraction (SLE), ultrasound assisted extraction (UAE) and pressurized liquid extraction (PLE). Furthermore, preliminary studies of the supercritical fluid extraction (SFE) of plane tree bark are also reported. The liquid solvent based extraction techniques (SLE, UAE and PLE) were carried out using ethanol and ethyl acetate, and produced a recovery of betulinic acid in the range 10-15 mg/g of bark, with concentrations around 25-35% mass. A betulinic acid enrichment in the ethanolic extracts was possible by means of a simple precipitation step adding water. The precipitate contained 42-46% mass of betulinic acid and high recovery (>95%). Increasing the extraction temperature, by means of the PLE assays, has not resulted in an improvement of betulinic acid recovery. The preliminary SFE assays produced lower recoveries of betulinic acid (0.5-8 mg/g) with respect to liquid extraction. The addition of ethanol as cosolvent produced a significant improvement of both betulinic acid recovery and concentration in the SFE extract., This work has been supported by project ALIBIRD-S2009/AGR-1469 from Comunidad Autónoma de Madrid. López-Padilla A. thanks to COLCIENCIAS (568–2012) and Medellin Mayor's Office (Sapiencia/Enlaza Mundos Program, 2013) for the Ph.D. fellowship.

This paper reports experimental data on the pressurized liquid extraction of caffeine from green coffee beans and green tea leaves using ethyl lactate (ethyl 2-hydroxy-propanoate). This solvent is a new bio-renewable agrochemical solvent, naturally produced by fermentation from corn derived feedstock, which has been recently considered as a very suitable and environmental benign solvent for food industrial applications. Static extraction assays (one step during 10 min) were carried out in an Accelerated solvent extraction (ASE) system at three different extraction temperatures, namely 100, 150 and 200 C. Extraction yield and caffeine recovery were determined and compared with those obtained when using other liquid solvents, such as ethyl acetate or ethanol. High recovery of caffeine (≈60%) was found in the extracts produced using ethyl lactate, which demonstrates the potential use of this green solvent for the extraction of caffeine from different vegetable sources. © 2012 The Institution of Chemical Engineers., The authors gratefully acknowledge the financial support from the Ministerio de Ciencia e Innovación of Spain (joined project Spain-Portugal, PT2009-0010) and the financial support from the Conselho de Reitores das Universidades Portuguesas (CRUP) – Integrated project Portugal – Spain, No. E-95/10. P. Luna and D. Villanueva acknowledges, respectively, the postdoctoral and predoctoral contract (JAE) given by the Consejo Superior de Investigaciones Científicas (CSIC) of Spain. M.S. Manic is thankful to Fundação para a Ciência e Tecnologia – Portugal for a doctoral fellowship (SFRH/BD/45323/2008).

Supercritical fluid chromatography (SFC) in analytical and semi-preparative scale was studied to separate rosemary (Rosmarinus officinalis) supercritical extracts to produce fractions with high antioxidant activity. Carnosic acid, the major antioxidant present in rosemary supercritical extracts, was the target compound to be isolated in the fractions produced. First, rosemary extracts were produced in a supercritical CO2 pilot-plant employing different extraction conditions, in order to obtain samples with diverse composition. The content of carnosic acid was determined and the DPPH test was accomplished in order to assess the antioxidant activity of the different samples produced. Then, using some of these samples, experiments were carried out in a semi-preparative SFC system testing the performance of four different chromatographic columns to isolate and recover a fraction with high concentration of carnosic acid. The four chromatographic columns employed were silica and 2-ethylpyridine (especially packed for SFC) and silica and diol columns (packed for HPLC). The SFC fractionation conditions explored were in the ranges 10-20MPa, 313-333K and 5-20% of cosolvent (ethanol). Using the first three columns, it was possible to isolate fractions with concentrations of carnosic acid greater than 80% mass. © 2013 Elsevier B.V., This work has been financed by project AGL2010-21565 (subprogram ALI) and project INNSAMED IPT-300000-2010-34 (subprogram INNPACTO) from Ministerio de Ciencia e Innovación (Spain).

Mixed vegetal extracts are interesting target of new products as nutraceuticals, superior ingredients for the design of functional food, singular ingredients for cosmetics, etc. In this work the extraction of a mixture of spinach and rosemary leaves (50 wt.% of each plant) was investigated in terms of its antioxidant activity, and compared with the extraction of the separate species. Phenolic diterpenes of rosemary and carotenoids of spinach were target compounds due their recognized biological activities. Two different extraction techniques were applied, namely pressurized liquid extraction using hexane at two different temperatures (100 and 150 C) and supercritical fluid extraction with pure carbon dioxide at 40 C and two different pressures (20 and 30 MPa). For each extraction technique and conditions three different raw materials were employed: spinach leaves, rosemary leaves and the mixture 50:50 of spinach and rosemary leaves. The antioxidant activity of the samples produced was evaluated with the ABTS assay and showed to be enhanced when the species are simultaneously extracted, with antioxidant values around 20% higher than the values corresponding to mixing the extracts obtained by separate. A possible synergic effect between carotenoids and phenolic diterpenes was studied, although no specific synergic activity could be observed. However, the enhanced antioxidant activity could be attributed to a definite increase of the concentration of carnosic acid, which was observed in the samples produced by the simultaneous extraction. © 2013 Elsevier B.V. All rights reserved., This work has been supported by project INNSAMED IPT-300000-2010-34 (subprogram INNPACTO) from Ministry of Science and Innovation (Spain) and project ALIBIRD-S2009/AGR-1469 from Autonomous Community of Madrid.

A supercritical CO 2 pilot plant was employed to extract rosemary (Rosmarinus officinalis L.) leaves and to thoroughly study the effect of time on the yield, composition and antioxidant activity of the different fractions produced. Six extraction assays were carried out, varying the fractionation procedure using a two-stage depressurization system coupled to the extractor vessel. The concentration of the main antioxidant compound in rosemary, i.e. carnosic acid, and the DPPH test were employed to evaluate the antioxidant power of the different fractions obtained. The goal was to develop a new fractionation scheme comprising two different periods of time, in which exhaustive extraction of the essential oil from the plant matrix was achieved while recovery of the antioxidant compounds was maximized., This work has been financed by project AGL2010-21565 (subprogram ALI) and project INNSAMED IPT-300000-2010-34 (subprogram INNPACTO) from the Ministerio de Ciencia e Innovación (Spain).

et al., (Solid + liquid) equilibria of binary mixtures containing high-value compounds and ethyl lactate were studied. Using the gravimetric method, the solubility of various solutes such as caffeine, vanillic acid, ferulic acid, caffeic acid and thymol in ethyl lactate was measured as a function of temperature over the range of (298.2 to 343.2) K, at atmospheric pressure. The differences in solubility of a given solute in water-saturated and dry ethyl lactate were observed. The deviation of these binary systems from ideal mixture behaviour was discussed. In order to understand the solubilization process, melting properties of pure solutes were determined by differential scanning calorimetry (DSC). The solubility data obtained were represented using UNIQUAC and UNIFAC-based models as well as with the Cubic-Plus-Association (CPA) equation of state. The results of the modeling indicate that these models are the appropriate tools for representing the solubility behaviour of various solutes in ethyl lactate. © 2011 Elsevier Ltd. All rights reserved., This work has been supported by Fundação para a Ciência e a Tecnologia through Grant No. PEst-C/EQB/LA0006/2011. The authors gratefully acknowledge the financial support from the Conselho de Reitores das Universidades Portuguesas (CRUP) – Integrated project Portugal – Spain, No. E-95/10 and from the Ministerio de Ciencia e Innovación of Spain (integrated project Spain-Portugal, PT2009- 0010). M.S. Manic is thankful to Fundação para a Ciência e Tecnologia – Portugal for a doctoral fellowship (SFRH/BD/45323/2008). D. Villanueva thanks for the JAE-pre fellowship given by Consejo Superior de Investigaciones Científicas (CSIC) of Spain.

El pdf del artículo es la versión pre-print., The supercritical CO 2 extraction of four different plants from Lamiaceae family, namely oregano (Origanum vulgare), thyme (Thymus zygis), sage (Salvia officinalis) and rosemary (Rosmarinus officinalis) was carried out in an experimental pilot-plant comprising an extraction cell of 2 L capacity. 600 g of leaves of each plant material, with the same pre-treatment, were extracted at the same pressure and temperature (30 MPa and 313 K) and using 2.4 kg/h of CO 2. Further, the same fractionation procedure in a two on-line decompressing separators at, respectively, 10 MPa and 0.1 MPa was employed. In this way, a thoughtful comparison of the extraction kinetic was established and discussed, in terms of the extraction yields attained in the separators, the variation of the essential oil composition with time and the content of key bioactive substances identified in the different fractions. © 2012 Elsevier B.V. All rights reserved., The authors gratefully acknowledge the financial support from the Comunidad Autónoma de Madrid (ALIBIRD, project number S-2009/AGR-1469) and the Ministerio de Educación y Ciencia (CONSOLIDER-INGENIO, CSD 2007-00063).

A comparative study of the oxidative stability of >ultra-high> ω3 concentrates (80%) from fish oils as triacylglycerols (TAG) or ethyl esters (EE), as well as their stabilization by supercritical extracts of rosemary (SER), α-tocopherol or their mixture, by Rancimat method and throughout storage time, was carried out. No significant differences were found between EE and TAG on oxidative stability when measured by Rancimat conditions in the range of 50-90°C. However, storage experiments revealed a poor stability of the EE concentrate form, measured by the monitorization of peroxide and p-anisidine values. Concerning the stabilization by antioxidants, there was a lack of antioxidant effect of evaluated compounds when Rancimat assays were performed at 70°C, whereas an antioxidant effect began to evidence at 60°C, and a clearest antioxidant protection was measured at 50°C for the mixture of the SER plus α-tocopherol in both EE and TAG forms. This selected binary mixture efficiently stabilized the ω3-TAG concentrate throughout 50. days of storage conditions, whereas the stabilization of ω3-EE concentrate was worse. Therefore, the combination of SER and α-tocopherol seemed to be a good antioxidant mixture for the efficient stabilization of extremely labile ultra-high ω3 concentrates, especially in the form of ω3 TAG oils. © 2011 Elsevier Ltd., The authors would like to thank the Spanish company Nutra Omega Biotecnologica Oleic S.L. (Project CENIT HIGEA CEN-20072003) and the Community of Madrid, Spain (ALIBIRD-CM S-2009/AGR-1469) for supporting this research. Diana Martin thanks the Ministerio de Ciencia e Innovacion and Fondo Social Europeo for funding her postdoctoral “Juan de la Cierva” contract.

Experimental and modeling studies of the liquid-liquid equilibria at ambient pressure of three model systems-squalene + ethyl lactate, olive oil + ethyl lactate, and squalene + olive oil + ethyl lactate-were performed with the view to explore the potential application of an agrochemical solvent, namely, ethyl lactate, to recover squalene from pretreated olive oil deodorizer distillate. The favorable separation factors obtained reveal the strength and potential of ethyl lactate as a green solvent for the recovery of squalene from squalene + triglyceride mixtures. © 2011 American Chemical Society.

El pdf del artículo es la versión pre-print., Rosmarinusofficinalis (rosemary) extracts were obtained in a supercriticalpilot-scale plant. Based on experimental information available in the literature for analytical or low-scale processes, extraction temperature and pressure were selected to be 313 K and 30 MPa. At these extraction conditions, the kinetic behavior of the pilot-scale overall extraction curve were determined with respect to yield, antioxidant activity and carnosic acid content. The overall extraction curve was represented using Sovova's model; the average deviation between measured and calculated yields was lower than 2%. Mass transfer coefficients in the fluid and solid phases were determined and were compared with previous data reported in the literature for low-scalerosemarysupercriticalextraction. A two-stage depressurization procedure was accomplished and the effect of both on-line fractionation and extraction time on the antioxidant activity of the samples collected was studied. The antioxidant activity of the different fractions could be straight correlated with the carnosic acid content with a regression coefficient of 0.92., This work has been financed by Universidad Autónoma de Madrid and Comunidad Autónoma de Madrid (ALIBIRDS2009/ AGR-1469) and project FUN-C-FOOD, CSD2007-00063 (CONSOLIDER-INGENIO) from Ministerio de Ciencia e Innovación, Spain.

The supercritical removal of ethanol from alcoholic beverages (brandy, wine, and cider) was studied using the GC-EoS model to represent the phase equilibria behavior of the CO2 + beverage mixture. Each alcoholic drink was represented as the ethanol + water mixture with the corresponding ethanol concentration (35 wt% for brandy, 9-12 wt% for different wines and 6 wt% for cider). The thermodynamic modeling was based on an accurate representation of the CO2 + ethanol and CO2 + water binary mixtures, and the CO2 + ethanol + water ternary mixture. The GC-EoS model was employed to simulate the countercurrent supercritical CO2 dealcoholization of the referred beverages; the results obtained compared good with experimental data from the literature. Thus, the model was used to estimate process conditions to achieve an ethanol content reduction from ca. 10 wt% to values lower than 1 wt%. The model results were tested by carrying out several extraction assays using wine, in a 3 m height packed column at 308 K, pressures in the range of 9-18 MPa and solvent to wine ratio between 9 and 30 kg/kg. © 2010 Elsevier B.V. All rights reserved.

The measurement and correlation of the high-temperature aqueous solubilities of three different carbohydrates (glucose, maltose, xylose, etc.) between 293 and 453 K are reported in this study. Sugar solubilities were measured by a continuous-flow technique in which the sugar is saturated at various temperatures in a stream of flowing hot water. Sugar solubilities were measured on the diluted samples taken in the "saturation plateau" region of the solubility measurement technique. Because of a large increase in the sugar solubility with temperature, particularly above the boiling point of water, adjustments in the size and amount of solute in the saturation cell as well as an adjustment of the dilution water rate were necessary. The determined sugar solubility values compare favorably with existing data below the boiling point of water and provide nonexisting data over the above temperature range above the boiling point of water. The resultant sugar solubility trends were modeled empirically or by use of a modified Apelblat equation or the A-UNIFAC model. © 2010 American Chemical Society.

Food-grade complex oligosaccharide mixtures manufactured commercially via transglycosylase reactions using disaccharides, such as sucrose or lactose as the raw material, are, in general, not pure products. Reducing oligosaccharides may be isomerized using borates and aluminates as complexating agents to obtain prebiotic oligosaccharides. Complexating agents are used to avoid side-reactions but are difficult to remove from mixture. In the present work, a new process based on the extraction with supercritical CO2 plus a co-solvent has been developed to purify reaction mixtures leading to pure prebiotic oligosaccharides. A three-step supercritical extraction process has been designed to purify carbohydrates according to its degree of polymerization; the appropriate selection of the co-solvent employed, together with the most suitable extraction conditions allowed the almost complete removal of monosaccharides, and disaccharides from the mixture, leading to pure oligosaccharides as a residue of the extraction process. In this process, not only complete fractionation of mono-, di- and trisaccharides was achieved but also elimination of borates and aluminates from the prebiotic carbohydrates mixture. © 2010 Elsevier B.V. All rights reserved.

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 degrees 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.

In the present work, the viability of the selective fractionation of carbohydrate mixtures (lactose-lactulose) using supercritical CO2 has been evaluated. As a first step towards the optimization of the fractionation process, the composition of the co-solvent used in the supercritical phase was studied by considering different ethanol:water mixtures, which undoubtedly determined the selectivity of the extraction process. The co-solvent which provided a purity higher than 95% in lactulose (a mixture ethanol:water 95:5) was selected to perform the optimization of the extraction conditions able to provide high extraction recoveries. Optimization was carried out using a full factorial (2 levels) design and considering as factors the extraction pressure (from 100 to 300 bar), the extraction temperature (from 60 to 100 °C) and the modifier flow rate (from 0.2 to 0.4 mL/min, which corresponded to a total co-solvent percentage ranging from 4 to 18 vol.%). The responses evaluated were the amount (mg) of lactulose and lactose extracted and their recoveries (%). The statistical analysis of the results provided mathematical models for each response variable. The corresponding parameters were estimated by multiple linear regression (MLR) and high determination coefficients (higher than 0.98) were obtained. Then, the mathematical model was employed to predict the behavior of the different responses selected, as a function of the main variables involved in the process. The optimum conditions for selectively extracting lactulose with high recoveries were 100 bar, 100 °C and 0.2 mL/min of co-solvent (4% modifier in the supercritical phase); at these conditions, a 45% recovery was achieved with a purity higher than 95%., F.M. thanks MEC for a FPI grant. T.F. would like to acknowledge the financial support of the Ramon y Cajal Program from the Ministry of Education and Science. This work has been financed under a R&D program of the Spanish Ministry of Education and Science, project AGL-2004-07227-C02-02 and project S-0505/AGR/000153 from the Comunidad Autónoma de Madrid.