<p>U radu su prikazani eksperimentalni rezultati natkritične ekstrakcije etarskog ulja bobica<br />kleke (<em>Juniperus communis</em> L.) i ulja iz semena uljane tikve golice (<em>Cucurbita pepo</em> L.). Ispitan je uticaj pritiska, temperature, stepena usitnjenosti čestica i protoka natkritičnog<br />ugljendioksida na promenu prinosa ulja sa vremenom. U cilju poređenja, usitnjeno seme uljane tikve ekstrahovano je i u ekstraktoru većih dimenzija, NOVA-SWISS, High<br />pressure extraction plant, kao i heksanom i petroletrom u ekstraktoru tipa Sokslet.<br />Praćena je i promena kvaliteta ekstrakata sa vremenom: u etarskom ulju kleke, GC-FID i GC-MS metodama, određen je relativni sadržaj 50 terpenskih jedinjenja i sve komponente ulja su svrstane u 5 osnovnih grupa (monoterpene, seskviterpene, oksidovane monoterpene, oksidovane seskviterpene i ostale komponente). U tikvinom ulju ekstrahovanom natkritičnim ugljendioksidom određen je masnokiselinski sastav GC-MS analizom, sadržaj tokoferola HPLC analizom, sterola i skvalena GC-MS metodom. Određeni su uslovi koji favorizuju ekstrakciju ispitanih jedinjenja za obe sirovine. Dat je dateljan prikaz matematičkih modela koji se koriste za opisivanje natkritične ekstrakcije etarskih ulja i masnih ulja, počev&scaron;i od najop&scaron;tijeg modela koji uključuje diferencijalne bilanse mase za rastvorak u masi natkritičnog fluida, u fluidu unutar pora čestica usitnjenog matrijala i u čvrstoj fazi, koji se uvođenjem određenih pretpostavki pojednostavljuje i svodi na modele koji su izabrani da budu ispitani u okviru ovoga rada. Ispitani su modeli kreireni po analogiji sa hlađenjem vrele kugle u masi fluida, tj. modeli tipa jedne sfere i to: Model jedne sfere-1 (MJS-1), koji pored uticaja koeficijenta efektivne difuzije ulja u materijalu na brzinu prenosa mase uzima u obzir uticaj koeficijenta prenosa mase kroz film natkritičnog fluida oko čestice, pri čemu je njegova vrednost procenjena preko postojećih korelacija; MJS-1 (2 par), u kome je spolja&scaron;nji koeficijent prenosa mase uzet kao drugi prilagodljiv parametar modela; MJS-2, gde je koeficijent efektivne difuzije jedini prilagođeni parametar, Model karakterističnog vremena i pro&scaron;ireni model klipnog toka koji je predložila Sovov&aacute;. Za modelovanje natkritične ekstrakcije ulja semena tikve kori&scaron;ćen je i kombinovani model Honga i sar. Softverskim paketima Mathcad 2001 Professional i Solver dodatka unutar Microsoft Excel 2003, određeni su parametri ispitanih modela u cilju najboljeg slaganja modela sa ekperimentalnim podacima. Za obe ispitane sirovine, među ispitanim modelima, izabrani su modeli koji najbolje opisuju njihovu ekstrakciju natkritičnim ugljendioksidom. Pro&scaron;ireni model klipnog toka koji je predložila Sovov&aacute; pokazao se podjednako dobrim za modelovanje natkritične ekstrakcije obe sirovine i ne&scaron;to bolji od ostalih primenjenih modela.</p> / <p>This study provides results of supercritical carbon dioxide (SCCO₂) extraction of juniper berries (<em>Juniperus communis</em> L.) and pumpkin seeds (<em>Cucurbita pepo</em> L. convar.&nbsp;<em>citrullina</em>) in a laboratorysupercritical fluid extraction apparatus. The influence<br />of pressure, temperature, particle size and carbon dioxide flow on the extraction kinetics of pumpkin seed oil and juniper berry essential oil was studied. Ground pumpkin seeds were also extracted with supercritical carbon dioxide in NOVA-SWISS, High Pressure Extraction Plant, and with hexane and petroleum ether in a laboratory Soxhlet extractor. This work was also aimed to investigate the evolution of the composition of juniper fruit supercritical CO₂ extracts with time, at different extraction pressures and to emphasize the most favorable condition for the extraction of different terpene hydrocarbon groups, reporting the qualitative differences among extracts collected during successive extraction time periods. Juniper berry extracts were analyzed by capillary gas chromatography, using flame ionization (GC-FID) and mass spectrometric detection (GC-MS). More than 200 constituents were detected in the extracts and the contents of 50 compounds were reported in the work. Dependence of the percentage yields of monoterpene, sesquiterpene, oxygenated monoterpene and oxygenated sesquiterpene hydrocarbon groups on extraction time was investigated and conditions that favored the yielding of each terpene groups were emphasized. GC-MS analysis of FAME, prepared by transesterification of pumpkin seed oil with KOH in methanol, was performed. Fatty acid compositions of supercritical CO₂ pumpkin seed extract fractions collected in successive time intervals over the course of the extraction were determined. The same fractions were analyzed by high pressure liquid chromatography (HPLC), using diode-array detector (DAD) in order to determine a- and g-tocopherol contents. Sterol and squalene contents were determined by GC-MS analysis, as well. Conditions that favored the yielding of tocopherols, squalene and sterols were emphasized. A general mass transfer model and its simlifications were analysed. Extraction curves were evaluated by &ldquo;hot sphere&rdquo; mathematical models SSM-1 (Single Sphere Model 1 &ndash; in which the external mass transfer coefficient also influences the extraction profile and film mass transfer coefficients were estimated by the correlations), SSM-1 (2 par) (film mass transfer coefficient is used as the second adjustable parameter), SSM-2 (only effective diffusivity influence is considered), Characteristic time model and by the extended Lack&rsquo;s plug-flow model given by Sovov&aacute;. A combined model of Hong et al. was also fitted to the experimental data for pumpkin seed oil SCCO_2&nbsp;extractions. Relative merits of the models are demonstrated. Good agreement between the extended Lack&rsquo;s plug-flow model and the experimental measurements was obtained.</p>

Although gas and liquid chromatography have emerged as dominant separation techniques in environmental analytical chemistry, these methods do not allow for the concurrent analysis of chemically diverse groups of persistent organic pollutants (POPs). There are also a small number of compounds which are not easily amenable to either of these traditional separation techniques. The main objective of this thesis was to address these issues by demonstrating the applicability of packed column supercritical fluid chromatography (pSFC) coupled to mass spectrometry (MS) in various aspects of environmental chemistry. First, pSFC/MS analytical methods were developed for legacy POPs (PCDDs, PCDFs, and PCBs) as well as the emerging environmental contaminant Dechlorane Plus (DP), and issues relating to the ionization of target analytes when pSFC was coupled to MS were explored. Novel APPI and APCI reagents (fluorobenzene and triethylamine) were optimized and real samples (water and soil) were analyzed to demonstrate environmental applicability. The possibility of chiral and preparative scale pSFC separations was then demonstrated through the isolation and characterization of thermally labile hexabromocyclododecane (HBCDD) stereoisomers. The analytical pSFC separation of the α-, β-, and γ-HBCDD enantiomers as well as the δ and ε meso forms was shown to be superior to results obtained using a published LC method. Finally, technical mixtures of phosphorus flame retardants (RBDPP, BPA-BDPP, and DOPO; a group of related compounds which are challenging to analyze concurrently) were examined using multiple analytical techniques and pSFC was found to be the only method which facilitated the accurate determination of the components of all 3 mixtures. This thesis confirms the potential of pSFC/MS as a fast, green, and cost effective means of separating and analyzing environmental contaminants.

In this project the photodegradation of 3,5-diamino-6-chloro-N-(2-(methylamino)ethyl)pyrazine-2-carboxamide was studied. A hypothetical degradation pattern for the compound was proposed and the aim of the project was to study the formed secondary photodegradants and to, if possible, structure elucidate some of these compounds. In order to do this, the parent compound was photodegraded in two steps, where a primary photodegradant was isolated using semi-preparative supercritical fluid chromatography (SFC) and then further degraded into the secondary photodegradants. The photodegradation was first carried out in aqueous solution, where the parent compound was irradiated in UV-A light of 300-400 nm. This resulted in a primary photodegradant with a molecular ion of m/z = 227, where the chloride in position 6 of the pyrazine group had been replaced by a hydroxyl group. During the large scale photodegradation, prior to the preparative purification, the yield of primary photodegradant was very low due to the photodegradation being dependent on both sample volume and concentration and due to the primary photodegradant also being unstable in aqueous solution at room temperature. Due to the above mentioned difficulties the parent compound was photodegraded in methanol instead of water in order to avoid the freeze-drying process where a lot of the primary photodegradant was lost. This resulted in a primary photodegradant with a molecular ion of m/z = 241, where the chloride had been replaced by a methoxy group instead of a hydroxyl group. This compound was more stable which allowed workup by rotary evaporation, instead of freeze-drying, before the preparative purification. This primary photodegradant was isolated using semi-preparative SFC on a Viridis® BEH Prep OBD TM column (250 x 30 mm, 5 µm) and a Luna HILIC column (250 x 30 mm, 5 µm) with MeOH/NH3 100/1 v/v as organic modifier. About 1.2 mg material was isolated and further photodegradation tests in ordinary water and 18O-water were conducted. Some secondary photodegradants were observed in LC-MS analyses, and their element compositions were proposed by accurate mass results. Fundamental structures for these compounds were proposed. Further structural investigational analyses are needed for confirmation in the future.

O grande acúmulo de saponinas nos frutos imaturos de erva mate permite considerá-los uma fonte de matéria prima abundante e ainda não explorada para obtenção de saponinas. As saponinas são conhecidas como tensoativos naturais, sendo utilizadas pelas suas propriedades emulsificantes e farmacológicas. O presente estudo teve como principal objetivo avaliar o uso de técnicas de extração emergentes, como Extração assistida por Ultrassom (US), Campo Elétrico Moderado (CEM) e Extração por Fluido Supercrítico (EFS) para a extração seletiva de saponinas a partir de frutos imaturos de erva mate. Foram investigadas três condições de intensidade de ultrassom (565, 423 e 282 W cm-²) e de intensidade de campo elétrico (50, 37,5 e 25 V cm-1) associadas a diferentes temperaturas de operação. A interação das intensidades de ultrassom e de campo elétrico com diferentes temperaturas foi avaliada através do método de superfície de resposta. Para as extrações por fluido super e sub crítico foram utilizadas três condições de pressão (10, 20 e 30 MPa) e posteriormente sua correlação com diferentes vazões de solvente (1,62; 2,22 e 2,78 x10-4 kg s-1) e temperatura (30, 40 e 50 °C) foi investigada através do métodos de superfície de resposta. Curvas de rendimento das extrações em função do tempo foram levantadas para as condições ótimas de campo elétrico e intensidade de ultrassom (37,5 V cm-1 e 565 W cm-², respectivamente) a 40°C. As curvas foram modeladas matematicamente, com ajuste satisfatório, por modelos cinéticos de 1ª e 2ª ordem e também por um modelo difusivo baseado na 2ª Lei de Fick. Para extração supercrítica, foi construída a curva de extração para a condição de 10 MPa e 40 °C e esta curva foi modelada matematicamente. Assim, foram estimados parâmetros relacionados à transferência de massa, importantes para a compreensão fenomenológica dos processos extrativos. Nesse estudo, a extração com CO2 supercrítico mostrou-se tecnicamente viável para a obtenção de saponinas, sendo mais seletiva em relação aos processos por campo elétrico e ultrassom. Os ensaios com ultrassom e campo elétrico conseguiram gerar extratos brutos com até 68,30 e 64,26 μgilexmg-1extrato em massa de equivalente de saponina por massa de extrato, respectivamente. Os extratos obtidos com fluido supercrítico apresentaram elevada seletividade para saponinas, gerando extratos brutos com até 100,9 μgilex mg-1 extrato de saponina por massa de extrato. A pressão de operação não apresentou efeito tanto no rendimento global de extrato quanto no de saponina. / Considering the substantial amount of saponins in unripe yerba mate fruits, they are an abundant source of raw material not exploited yet. Saponins are known as natural surfactants, being used by their emulsifier and pharmacological properties. This study aimed to evaluate emergent extraction techniques such as Ultrasound (US), Moderate Electric Field (MEF) and Supercritical Fluid Extraction (SFE) for the selective extraction of saponins from unripe fruits of yerba mate. Three power conditions (565, 423 and 282W cm-2), electric field intensities (50, 37.5 and 25 V cm-1) and pressure conditions (10, 20 and 30 MPa) were initially assayed for US, MEF and SFE respectively at 40 °C. Power and electric field intensity were found to affect the saponins yields, thus, their correlation with different temperatures were evaluated with a factorial design. At the optimal condition, US and MEF saponins yields were 6.42% and 6.83% (%gilex gextract-1). Extraction yield curves were raised for optimum conditions of electric field and ultrasound power (37.5 V cm-1 and 565 W cm-², respectively). Three different kinetic models were used to model mathematically the overall extraction curves, namely a first-order, second-order, and a mass transfer model based on Fick’s Law. The operating pressure had no effect on either the overall brute extract or saponins yield for SFE. Although the extracts obtained with supercritical fluid showed low brute extracts yields, it was highly selective for saponins yielding up to 10.09%. For supercritical extraction, the extraction curve for 10 MPa and 40 °C was assayed and the experimental data fitted by a mathematical model. Parameters related to mass transfer, important for understanding of the extractive processes, were successfully estimated. In this study, the extraction with ultrasounds, electric field and supercritical CO2 were shown to be technically viable to obtain saponins from unripe yerba mate fruits, being EFS more selective than the other technics studied.

O presente trabalho investiga a aplicação do processo de extração com fluido supercrítico (EFS) para a obtenção de compostos fenólicos a partir de Butia capitata, coletado na Região Sul do Brasil. A planta, chamada popularmente de butiá, é uma espécie nativa da Argentina, Uruguai, Paraguai e Brasil. Os frutos do butiá são comestíveis e bastante apreciados pelas populações locais, que os consomem ao natural ou na forma de licores, geléias ou doces. Estudos recentes revelam que compostos fenólicos estão presentes nos frutos do butiá. Estes compostos merecem atenção por apresentarem atividade antioxidante, por prevenirem doenças cardiovasculares e reduzirem o risco de câncer. Atualmente existem diferentes formas para a obtenção de compostos fenólicos presentes em matrizes vegetais, porém muitas delas utilizam solventes orgânicos a altas temperaturas, o que deprecia o valor comercial dos extratos. Neste estudo, é utilizada uma tecnologia limpa, que tem como solvente o dióxido de carbono (CO2) em condições supercríticas. O CO2 é não-tóxico e não-inflamável, o que faz dele uma opção mais segura, quando comparado a outros solventes. Além disso, no estado supercrítico, o CO2 apresenta condições bastante favoráveis para a extração, como altas difusividades e massas específicas elevadas. Uma característica que deve ser ressaltada é a possibilidade de utilizar baixas temperaturas na extração, comparativamente aos processos que utilizam solventes líquidos, uma vez que os compostos fenólicos são termolábeis. Nos experimentos, foi utilizada apenas a polpa desidratada. O planejamento experimental foi elaborado avaliando a influência de três variáveis de processo em três níveis: pressão (150, 200 e 250 bar), temperatura (40, 50 e 60°C) e teor de cossolvente (1, 3 e 5% de etanol). Os extratos obtidos foram analisados em cromatografia líquida de alta eficiência (CLAE), sendo os rendimentos expressos em mg do composto identificado por CLAE /100g de polpa de butiá desidratada (PBD), e pelo método Folin-Ciocalteau com os rendimentos em compostos fenólicos totais (CFT) expressos em mg de rutina equivalente (RE)/100g PBD. Foram identificados cinco compostos majoritários nos extratos nas análises em CLAE. As maiores concentrações foram encontradas nas condições de 250 bar, 60°C e 5% de etanol. Os compostos identificados foram o ácido clorogênico (0,46mg/100g PBD), o ácido ferúlico (1,45mg/100g PBD), a rutina (3,47mg/100g PBD), a quercetina (0,90mg/100g PBD) e o canferol (1,93mg/100g PBD). Em termos de CFT, a melhor condição de extração foi de 200 bar, 50°C e 5% de etanol, resultando em 23,09mg RE/100g PBD. Os extratos também foram avaliados quanto ao poder de redução do radical DPPH•, pelo método IC50. O método fornece a quantidade necessária de extrato pra varrer 50% do radical. Como esperado, o extrato obtido na corrida experimental de maior rendimento em CFT apresentou maior atividade antioxidante (17,4 mg/mL), seguido da corrida experimental de maior rendimento em compostos fenólicos isolados (56,1 mg/mL) e, com menos atividade, o extrato obtido por solvente orgânico (80,0 mg/mL). / In this work it is investigated the application of supercritical fluid extraction to obtain phenolic compounds from Butia capitata, collected in southern Brazil. This plant, known popularly as butiá, is a native species in Argentina, Uruguay, Paraguay and Brazil. The edible fruits are popular and eaten raw or as liqueurs, jellies or jams. In recent studies, it is shown that phenolic compounds are present in the fruits of butiá. These compounds deserve attention because they have antioxidant activity, preventing cardiovascular disease and reducing the risk of cancer. There are different processes to obtain phenolic compounds from plant matrices, but many of them make use of organic solvents at high temperatures, which depreciates the extract value. In this study, it is used a clean technology, with carbon dioxide (CO2) as solvent in supercritical conditions. The CO2 is nontoxic and nonflammable that makes it a safer option than other solvents. Furthermore, in supercritical conditions the CO2 has favorable conditions for extraction, as high diffusivities and densities. A feature that should be emphasized is the possibility of using low temperatures in the extract, when compared to processes using liquid solvents, since the phenolic compounds are decomposed by high temperature. In the experiments only the dried pulp was used. The experimental design was developed to assess the influence of three process variables at three levels: pressure (150, 200 e 250 bar), temperature (40, 50 e 60°C) and cosolvent content (1, 3 e 5% of ethanol). The extracts were analyzed by high performance liquid chromatography (HPLC), in which the yields were expressed in terms of mg of the identified phenolic compounds by HPLC/100g of dried pulp and by the Folin-Ciocalteau method, with yields, as total phenolic compounds, expressed in mg of rutin equivalent/100g of dried pulp. It were identified five majority phenolic compounds by HPLC. Its highest concentrations were found in the conditions of 250 bar, 60°C and 5% of cosolvent. The identified compounds were chlorogenic acid (0,46mg/100g of dried pulp), ferulic acid (1,45mg/100g of dried pulp), rutin (3,47mg/100g of dried pulp), quercetin (0,90mg/100g of dried pulp) and kaempferol (1,93mg/100g of dried pulp). In terms of total phenolic compounds, the best conditions were 200 bar, 50°C and 5% of cosolvent, which resulted in 23,09mg of rutin equivalent/100g of dried pulp. Also, the antioxidant activity of the extracts was measured by scavenging of the DPPH• radical, by the IC50 method. The method provides the necessary amount of extract to scavenging 50% of the radial. As expected, the extract obtained in experimental run with the highest yield in CFT showed a higher antioxidant activity (17.4 mg / mL), followed by the experimental run with the highest yield in phenolic compounds isolated (56.1 mg / mL), and, with less activity, the extract obtained by organic solvent (80.0 mg / mL).

Supercritical fluid extraction has been used to recover biomaterials from natural matrices. Mathematical modeling of the extraction is required for process design and scale up. Existing models in literature are correlative and dependent upon the experimental data. Construction of predictive models giving reliable results in the lack of experimental data is precious. The long term objective of this study was to construct a predictive mass transfer model, representing supercritical fluid extraction of biomaterials in packed beds by the method of volume averaging. In order to develop mass transfer equations in terms of volume averaged variables, velocity and velocity deviation fields, closure variables were solved for a specific case and the coefficients of volume averaged mass transfer equation for the specific case were computed using one and two-dimensional geometries via analytical and numerical solutions, respectively. Spectral Element method with Domain Decomposition technique, Preconditioned Conjugate Gradient algorithm and Uzawa method were used for the numerical solution. The coefficients of convective term with additional terms of volume averaged mass transfer equation were similar to superficial velocity. The coefficients of dispersion term were close to diffusivity of oil in supercritical carbon dioxide. The coefficients of interphase mass transfer term were overestimated in both geometries. Modifications in boundary conditions, change in geometry of particles and use of three-dimensional computations would improve the value of the coefficient of interphase mass transfer term.

Ingestion of extracts prepared from various medicinal plants to induce or augment labour is common amongst Black South African women during the late stages of pregnancy. This applies particularly to the rural areas where modern health care facilities are often lacking. Many of these plants have not been investigated scientifically and one needs to substantiate claims of quality, safety and efficacy. Furthermore, it is believed that the consumption of these plant extracts can result in foetal meconium staining at delivery. An investigation into the uterotonic properties of three plants viz. Ekebergia capensis Sparrm. Clivia miniata (Lindl.) Regel. and Grewia occidentalis L. were carried out using guinea pig uterine smooth muscle in vitro. Supercritical fluid extraction was performed with water modified supercritical carbon dioxide to extract the uterotonic components. An attempt was also made to couple supercritical fluid extraction directly on-line to the bioassay so that on line screening of crude plant extracts could be performed within short periods of time. The effects of supercritical CO2 decompression on temperature and pH of the muscle bathing solution were considered since these factors affect muscle contractility. The direct effects of excess CO2 on intracellular mechanisms were eliminated by constructing a CO2 reduction interface together with passage of carbogen which aided in the rapid displacement of excess CO2, As samples of these extracts were found to induce muscle contraction, supercritical fluid fractionation (SFF) was performed by sequentially increasing the fluid density. Extracted fractions were obtained by sequentially increasing the pressure at constant temperature and modifier concentration in an attempt to identify the active fractions. Extractions were performed at 200 atm, 300 atm and 400 atm respectively. Subsequent testing of these fractions enabled the detection of active and inactive fractions as well as a fraction that had a spasmolytic effect on uterine muscle. The 400 atm extracts of E. capensis and C. miniata displayed maximum activity while only the 300 atm extract of G. occidentalis induced uterine muscle contraction. Subsequent analysis of the sequentially extracted fractions, by high performance liquid chromatography and micellar electrokinetic capillary chromatography revealed that certain compounds present in the fractions that stimulated muscle contraction, were sensitive to the extraction pressure hence making it possible to determine the compounds that were likely to be active. Column chromatography followed by various spectroscopic techniques were performed in an attempt to isolate and elucidate the structures of the compounds that were present in the plant extracts. The extract of Ekebergia capensis yielded five known compounds (B-sitosterol, oleanonic acid, 3-epioleanolic acid, 2,3,22,23-tetrahydroxy-2,6,1 0, 15,19 ,23-hexamethyl-6, 10, 14, 18- tetracosatetrene and 7-hydroxy-6-methoxy coumarin. The extract of Clivia miniata yieded linoleic acid and 5-hydroxymethyl-2-furancarboxaldehyde while the extract of Grewia occidentalis yielded 3-(4-hydroxy-3-methoxyphenyl)-2-propenal, a novel compound 2,2' ,6,6'-tetramethoxy-4'-al-4-(w-oxo-E-propenyl)-biphenyl and oleanonic acid. The pure compounds were further evaluated pharmacologically to identify the active components and assess the physiological mode of action by the use of various receptor blockers. Oleanonic acid, 3-epioleanolic acid, linoleic acid and 5- hydroxymethyl-2-furancarboxaldehyde and 3-(4-hydroxy-3-methoxyphenyl)-2-propenal were found to induce an agonistic muscle response. All these compounds were observed to mediate their effects through the cholinergic receptors. The results obtained in this study supports the claim of these plants possessing uterotonic properties. / Thesis (Ph.D.)-University of Natal, Durban, 1997.

Thesis (M.S.B.E.)--University of South Florida, 2009. / Title from PDF of title page. Document formatted into pages; contains 108 pages. Includes bibliographical references.

O presente trabalho investiga a aplicação do processo de extração com fluido supercrítico (EFS) para a obtenção de compostos fenólicos a partir de Butia capitata, coletado na Região Sul do Brasil. A planta, chamada popularmente de butiá, é uma espécie nativa da Argentina, Uruguai, Paraguai e Brasil. Os frutos do butiá são comestíveis e bastante apreciados pelas populações locais, que os consomem ao natural ou na forma de licores, geléias ou doces. Estudos recentes revelam que compostos fenólicos estão presentes nos frutos do butiá. Estes compostos merecem atenção por apresentarem atividade antioxidante, por prevenirem doenças cardiovasculares e reduzirem o risco de câncer. Atualmente existem diferentes formas para a obtenção de compostos fenólicos presentes em matrizes vegetais, porém muitas delas utilizam solventes orgânicos a altas temperaturas, o que deprecia o valor comercial dos extratos. Neste estudo, é utilizada uma tecnologia limpa, que tem como solvente o dióxido de carbono (CO2) em condições supercríticas. O CO2 é não-tóxico e não-inflamável, o que faz dele uma opção mais segura, quando comparado a outros solventes. Além disso, no estado supercrítico, o CO2 apresenta condições bastante favoráveis para a extração, como altas difusividades e massas específicas elevadas. Uma característica que deve ser ressaltada é a possibilidade de utilizar baixas temperaturas na extração, comparativamente aos processos que utilizam solventes líquidos, uma vez que os compostos fenólicos são termolábeis. Nos experimentos, foi utilizada apenas a polpa desidratada. O planejamento experimental foi elaborado avaliando a influência de três variáveis de processo em três níveis: pressão (150, 200 e 250 bar), temperatura (40, 50 e 60°C) e teor de cossolvente (1, 3 e 5% de etanol). Os extratos obtidos foram analisados em cromatografia líquida de alta eficiência (CLAE), sendo os rendimentos expressos em mg do composto identificado por CLAE /100g de polpa de butiá desidratada (PBD), e pelo método Folin-Ciocalteau com os rendimentos em compostos fenólicos totais (CFT) expressos em mg de rutina equivalente (RE)/100g PBD. Foram identificados cinco compostos majoritários nos extratos nas análises em CLAE. As maiores concentrações foram encontradas nas condições de 250 bar, 60°C e 5% de etanol. Os compostos identificados foram o ácido clorogênico (0,46mg/100g PBD), o ácido ferúlico (1,45mg/100g PBD), a rutina (3,47mg/100g PBD), a quercetina (0,90mg/100g PBD) e o canferol (1,93mg/100g PBD). Em termos de CFT, a melhor condição de extração foi de 200 bar, 50°C e 5% de etanol, resultando em 23,09mg RE/100g PBD. Os extratos também foram avaliados quanto ao poder de redução do radical DPPH•, pelo método IC50. O método fornece a quantidade necessária de extrato pra varrer 50% do radical. Como esperado, o extrato obtido na corrida experimental de maior rendimento em CFT apresentou maior atividade antioxidante (17,4 mg/mL), seguido da corrida experimental de maior rendimento em compostos fenólicos isolados (56,1 mg/mL) e, com menos atividade, o extrato obtido por solvente orgânico (80,0 mg/mL). / In this work it is investigated the application of supercritical fluid extraction to obtain phenolic compounds from Butia capitata, collected in southern Brazil. This plant, known popularly as butiá, is a native species in Argentina, Uruguay, Paraguay and Brazil. The edible fruits are popular and eaten raw or as liqueurs, jellies or jams. In recent studies, it is shown that phenolic compounds are present in the fruits of butiá. These compounds deserve attention because they have antioxidant activity, preventing cardiovascular disease and reducing the risk of cancer. There are different processes to obtain phenolic compounds from plant matrices, but many of them make use of organic solvents at high temperatures, which depreciates the extract value. In this study, it is used a clean technology, with carbon dioxide (CO2) as solvent in supercritical conditions. The CO2 is nontoxic and nonflammable that makes it a safer option than other solvents. Furthermore, in supercritical conditions the CO2 has favorable conditions for extraction, as high diffusivities and densities. A feature that should be emphasized is the possibility of using low temperatures in the extract, when compared to processes using liquid solvents, since the phenolic compounds are decomposed by high temperature. In the experiments only the dried pulp was used. The experimental design was developed to assess the influence of three process variables at three levels: pressure (150, 200 e 250 bar), temperature (40, 50 e 60°C) and cosolvent content (1, 3 e 5% of ethanol). The extracts were analyzed by high performance liquid chromatography (HPLC), in which the yields were expressed in terms of mg of the identified phenolic compounds by HPLC/100g of dried pulp and by the Folin-Ciocalteau method, with yields, as total phenolic compounds, expressed in mg of rutin equivalent/100g of dried pulp. It were identified five majority phenolic compounds by HPLC. Its highest concentrations were found in the conditions of 250 bar, 60°C and 5% of cosolvent. The identified compounds were chlorogenic acid (0,46mg/100g of dried pulp), ferulic acid (1,45mg/100g of dried pulp), rutin (3,47mg/100g of dried pulp), quercetin (0,90mg/100g of dried pulp) and kaempferol (1,93mg/100g of dried pulp). In terms of total phenolic compounds, the best conditions were 200 bar, 50°C and 5% of cosolvent, which resulted in 23,09mg of rutin equivalent/100g of dried pulp. Also, the antioxidant activity of the extracts was measured by scavenging of the DPPH• radical, by the IC50 method. The method provides the necessary amount of extract to scavenging 50% of the radial. As expected, the extract obtained in experimental run with the highest yield in CFT showed a higher antioxidant activity (17.4 mg / mL), followed by the experimental run with the highest yield in phenolic compounds isolated (56.1 mg / mL), and, with less activity, the extract obtained by organic solvent (80.0 mg / mL).

O grande acúmulo de saponinas nos frutos imaturos de erva mate permite considerá-los uma fonte de matéria prima abundante e ainda não explorada para obtenção de saponinas. As saponinas são conhecidas como tensoativos naturais, sendo utilizadas pelas suas propriedades emulsificantes e farmacológicas. O presente estudo teve como principal objetivo avaliar o uso de técnicas de extração emergentes, como Extração assistida por Ultrassom (US), Campo Elétrico Moderado (CEM) e Extração por Fluido Supercrítico (EFS) para a extração seletiva de saponinas a partir de frutos imaturos de erva mate. Foram investigadas três condições de intensidade de ultrassom (565, 423 e 282 W cm-²) e de intensidade de campo elétrico (50, 37,5 e 25 V cm-1) associadas a diferentes temperaturas de operação. A interação das intensidades de ultrassom e de campo elétrico com diferentes temperaturas foi avaliada através do método de superfície de resposta. Para as extrações por fluido super e sub crítico foram utilizadas três condições de pressão (10, 20 e 30 MPa) e posteriormente sua correlação com diferentes vazões de solvente (1,62; 2,22 e 2,78 x10-4 kg s-1) e temperatura (30, 40 e 50 °C) foi investigada através do métodos de superfície de resposta. Curvas de rendimento das extrações em função do tempo foram levantadas para as condições ótimas de campo elétrico e intensidade de ultrassom (37,5 V cm-1 e 565 W cm-², respectivamente) a 40°C. As curvas foram modeladas matematicamente, com ajuste satisfatório, por modelos cinéticos de 1ª e 2ª ordem e também por um modelo difusivo baseado na 2ª Lei de Fick. Para extração supercrítica, foi construída a curva de extração para a condição de 10 MPa e 40 °C e esta curva foi modelada matematicamente. Assim, foram estimados parâmetros relacionados à transferência de massa, importantes para a compreensão fenomenológica dos processos extrativos. Nesse estudo, a extração com CO2 supercrítico mostrou-se tecnicamente viável para a obtenção de saponinas, sendo mais seletiva em relação aos processos por campo elétrico e ultrassom. Os ensaios com ultrassom e campo elétrico conseguiram gerar extratos brutos com até 68,30 e 64,26 μgilexmg-1extrato em massa de equivalente de saponina por massa de extrato, respectivamente. Os extratos obtidos com fluido supercrítico apresentaram elevada seletividade para saponinas, gerando extratos brutos com até 100,9 μgilex mg-1 extrato de saponina por massa de extrato. A pressão de operação não apresentou efeito tanto no rendimento global de extrato quanto no de saponina. / Considering the substantial amount of saponins in unripe yerba mate fruits, they are an abundant source of raw material not exploited yet. Saponins are known as natural surfactants, being used by their emulsifier and pharmacological properties. This study aimed to evaluate emergent extraction techniques such as Ultrasound (US), Moderate Electric Field (MEF) and Supercritical Fluid Extraction (SFE) for the selective extraction of saponins from unripe fruits of yerba mate. Three power conditions (565, 423 and 282W cm-2), electric field intensities (50, 37.5 and 25 V cm-1) and pressure conditions (10, 20 and 30 MPa) were initially assayed for US, MEF and SFE respectively at 40 °C. Power and electric field intensity were found to affect the saponins yields, thus, their correlation with different temperatures were evaluated with a factorial design. At the optimal condition, US and MEF saponins yields were 6.42% and 6.83% (%gilex gextract-1). Extraction yield curves were raised for optimum conditions of electric field and ultrasound power (37.5 V cm-1 and 565 W cm-², respectively). Three different kinetic models were used to model mathematically the overall extraction curves, namely a first-order, second-order, and a mass transfer model based on Fick’s Law. The operating pressure had no effect on either the overall brute extract or saponins yield for SFE. Although the extracts obtained with supercritical fluid showed low brute extracts yields, it was highly selective for saponins yielding up to 10.09%. For supercritical extraction, the extraction curve for 10 MPa and 40 °C was assayed and the experimental data fitted by a mathematical model. Parameters related to mass transfer, important for understanding of the extractive processes, were successfully estimated. In this study, the extraction with ultrasounds, electric field and supercritical CO2 were shown to be technically viable to obtain saponins from unripe yerba mate fruits, being EFS more selective than the other technics studied.