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Plant extracts are being studied in the development of novel edible food coatings. The antioxidant and antimicrobial compounds that naturally occur in some plants are the key substances that contribute to preserving food quality. Besides the plant material, the method utilized to produce the extract influences its chemical and preservative characteristics. In general, hydrodistillation produce plant products (essential oils) that are well recognized for containing high concentration of antioxidant or antimicrobial volatile compounds. Supercritical fluid technology produces high quality bioactive extracts with higher yield but lower concentration of volatile compounds, in comparison with hydrodistillation. In this work, six different natural extracts of five different plants were produced by hydrodistillation and supercritical fluid extraction, and their antioxidant and antimicrobial activities were compared. The most active extracts were used to produce chitosan-based edible coatings with the aim of assessing the effect of essential oils versus supercritical extracts on the preservation of strawberries., The authors gratefully acknowledge the financial support from Comunidad de Madrid through the Programa de I+D en Tecnologías, Spain (ALIBIRD-CM S2013/ABI-2728). Somaris E. Quintana is grateful for the funding provided by Gobernación de Bolivar and Fundación Ceiba, Colombia. Olimpia Llalla is grateful to Programa Nacional de Innovación Agraria-PNIS of Perú (Contract No. 152-2018-INIA-PNIA-PASANTIA).

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”.

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).

Ethanol extracts (EE) from fenugreek and quinoa seeds with different total content of inhibitory compounds (TIC, total saponin plus phenolic) were prepared with and without concentration of TIC (CEE –concentrated EE-, and EE, respectively). Their inhibitory activity on pancreatic lipase and α-amylase was assessed by traditional in vitro methods (with or without orbital shaking), and by simulating intestinal digestion. CEE contained higher contents of TIC than EE, being fenugreek superior to quinoa (p, This work was supported by the Ministerio de Economía y Competitividad, Spain (AGL2016-76736-C3-1-R) and the Community of Madrid, Spain (ALIBIRD-CM S2013/ABI-2728). Teresa Herrera thanks the Community of Madrid for her contract (Fondo Social Europeo, Programa Operativo de Empleo Juvenil e Iniciativa de Empleo Juvenil YEI). Joaquín Navarro del Hierro thanks the Ministerio de Educación, Cultura y Deporte, Spain for funding his research with a FPU predoctoral contract (FPU 15/04236).

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).

Saponins are bioactive compounds of increasing interest. The events that take place during digestion are highly related to their bioactivities, because saponins are poorly absorbed and have a long residence time in the intestinal tract. The poor bioavailability of saponins is explained by a sum of factors, but the more favorable properties of sapogenins result in higher bioavailability and bioactivity. The gastric and colonic transformations of saponins are relevant in the release of sapogenins. Saponins inhibit enzymes and cholesterol absorption, but specific chemical structures of saponins are relevant for an efficient activity. Finally, the recent research has pointed to saponins as “prebiotic-like” compounds. This review summarizes the current knowledge on the events that take place during digestion of saponins and sapogenins related to their bioactivities, with special emphasis on the factors that modulate their bioavailability, bioaccessibility, inhibition of digestive enzymes and cholesterol absorption, and the importance of the microbiota-saponins relationship., This work was supported by the Ministerio de Economía y Competitividad, Spain (AGL2016-76736-C3-1-R) and the Community of Madrid, Spain (ALIBIRD-CM S2013/ABI-2728). Joaquín Navarro del Hierro thanks the Ministerio de Edución, Cultura y Deporte, Spain for funding his research with a FPU predoctoral contract (FPU 15/04236). Teresa Herrera thanks the Community of Madrid for her contract (Fondo Social Europeo, Programa Operativo de Empleo Juvenil e Iniciativa de Empleo Juvenil YEI).

The supercritical fluid extraction (SFE) of vegetal raw materials is a large field of research, innovation and entrepreneurial developments. Optimization of process conditions is usually accomplished in analytical or laboratory scale equipment. Although SFE scaling is essential to attain industrial applications, studies in the literature are scarce. In this work, the kinetic behavior of 19 overall extraction curves (OEC’s), obtained by the authors in previous works using NOVALINDUS Platform SFE facilities, and a set of 39 OEC’s published by other authors, were considered all together to study SFE scaling. A general trend between the solvent flow rate and Barton kinetic constant was obtained for all extraction curves included in the data base, which comprise 10 different plant materials, temperatures in the range 298–333 K, pressures of 10–30 MPa, extractor volumes from 50 to 5200 cm3, particle diameters from 250 to 1400 μm and bed porosity in the range 0.59–0.97., López-Padilla A. Thanks to COLCIENCIAS (568–2012) and Medellin Mayor’s Office (Sapiencia/Enlaza Mundos Program, 2013) for the Ph.D. fellowship. This work was financed thanks ALIBIRD, S2013/ABI-2728 (Comunidad de Madrid) project.

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).

Supercritical fluids have opened a wide range of new alternatives in food processing. Certainly, the most remarkable reason is the use of a substance permitted in foods, namely carbon dioxide (CO 2 ), as solvent.

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.

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).

The use of supercritical fluid technology as an innovative technology to extract bioactive compounds has grown considerably in recent decades. Particularly, the recovery of antioxidants from different herbs is a matter of continuous research and development. Antioxidants can protect cells against the effects of free radicals and thus, play an important role in heart illness, cancer and other diseases. Rosemary (Rosmarinus officinalis L.) has been recognized as one of the Lamiaceae plant with many important biological activities. Particularly, large antioxidant power has been recognized in rosemary and main substances related with this activity were the phenolic diterpenes such as carnosol, rosmanol, carnosic acid, methyl carnosate, and phenolic acids such as the rosmarinic and caffeic acids. Moreover, carnosic acid and carnosol are recognized as the most abundant antioxidants present in rosemary. In this work, supercritical fluid technology was applied to produce rosemary extracts with different compositions and thus, with different bioactivity properties. Selected extracts, from the variety of samples obtained, were used to study the capability of rosemary supercritical extracts to inhibit the proliferation of human liver carcinoma cells. These extracts showed a dose-dependent effect on inhibiting the proliferation of human hepatoma cells. Moreover, observed citostaticity appeared to be significantly influenced by their different composition, suggesting a relevant role of the technology to produce the extracts and the consequently obtained compositions on the potential antitumoral activity of rosemary. © 2012 Elsevier B.V. All rights reserved., This work has been financed by project AGL2010-21565 (subprogram ALI), RyC 2008-03734, and project INNSAMED IPT-300000-2010-34 (subprogram INNPACTO) from Ministerio de Ciencia e Innovación (Spain), Comunidad Autónoma de Madrid (project ALIBIRD-S2009/AGR-1469) and European Union Structural Funds.

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).

El pdf del artículo es la versión pre-print.-- et al., Supercritical CO2 extraction has been proved to be a potential tool in the recovery of aroma compounds from different natural sources and in the removal of ethanol from aqueous solutions. In this work, both ideas are combined to develop a two-step process toward the production of a low-alcohol beverage from wine, but maintaining the aroma and the antioxidant activity similar to that of the original wine. First, the recovery of aroma from wine was attained in a countercurrent packed column (white and red wines were investigated) using very low CO2/wine ratios. Then, the aroma-free wine recovered from the bottom of the extraction column was dealcoholized by applying different extraction conditions. The results obtained from these studies permit the design of a two-step countercurrent CO2 extraction process at 9.5 MPa and 313 K, in which the different CO2/wine ratios employed in each step lead to the recovery of aroma or the removal of ethanol. The two-step process was applied to rose wine and the low-alcohol beverage obtained proved to have similar antioxidant activity and similar aroma profile to that of the original wine. © 2011 Elsevier B.V. All rights reserved., The authors gratefully acknowledge the financial support from the Comunidad Autónoma de Madrid (ALIBIRD, project number S-505/AGR-0153) the Ministerio de Ciencia e Innovación (project AGL2007-64198/ALI), Spain and Miguel Torres S.A. (Proyect CENIT HIGEA CEN-20072003).

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.

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 relevant applications that supercritical fluid extraction (SFE) has attained in the food industry in the last decades increased the interest in the development of thermodynamic models to represent the phase equilibria of systems comprising food-related substances and supercritical carbon dioxide (SCCO 2). The targets are twofold: (i) calculation of solid solubilities in SCCO2 pure or with polar co-solvents (mainly ethanol in food applications), what directly affects the selectivity of one of the most applied processes, e.g. the semi-batch SFE of plant material, and (ii) calculation of vapor-liquid equilibrium compositions of liquid raw materials processed in countercurrent packed columns, what is straightforwardly related with the number of theoretical stages necessary to achieve the desired separation. Cubic equations of state derived from the equation proposed by van der Waals (vdW-type EoSs, e.g. Peng-Robinson and Soave-Redlich-Kwong EoS) are the most common thermodynamic models applied to achieve these objectives. In this work, the application of vdW-type EoSs to food-type substance + SCCO2 is reviewed. More than 100 systems, comprising lipids, antioxidants, pigments, alkaloids, vitamins, etc. were investigated from 2003 up today. Even though phase equilibria modeling of SCCO2 + food-related systems involves serious difficulties, the extensive and, in many cases, successful application of vdW-type EoSs demonstrates that though developed 100 years ago the van der Waals equation is lively and younger than before. © 2010 Elsevier B.V. All rights reserved.

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.

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.

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.