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Artykuły w czasopismach na temat "Solvents extracts":
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Kuznetsov, P. N., Z. R. Ismagilov, L. I. Kuznetsova, B. Avid, X. Fan i Е. S. Mihkailova. "The Composition and Properties of Soluble Products from the Coal ThermoSolvolysis with Hydrocarbon Residues and Blends as Solvents". Eurasian Chemico-Technological Journal 24, nr 3 (10.10.2022): 183–90. http://dx.doi.org/10.18321/ectj1431.
Streszczenie:
The dissolution of bituminous coal at mild temperature was studied using a variety of commercially available coal- and petroleum-derived hydrocarbon fractions, hydrorefined derivatives and blends as solvents. The chemical and molecular composition of the coal, solvents and extracts were characterized by chemical and group analyses, and by IRFT, 1H NMR, GC-MS and liquid chromatography. Low volatile solvents like highly aromatic coal tar (CT), its anthracene fraction (AFCT), petroleum-derived solvent (HGOCC) and binary blends were found to exhibit high performance for coal dissolution into quinoline solubles (to 79‒82%), and the yields of gases being no more than 0.5%. The extracts obtained using CT and AFCT solvents represented pitch-like matter consisting of rarely substituted aromatic molecules with 4‒5 condensed rings. HGOCC extract was much less aromatic, the aromatic rings being highly substituted with fairly large alkyl substituents. The blended solvents yielded more extracts, and their molecular indexes were average between those obtained with each solvent separately. A remarkable finding was that the extracts obtained were characterized by significantly lower content of benzo(a) pyrene (BaP) compared to solvents used, its content further decreased as the time of coal dissolution increased.
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Zakaria, F., B. A. Talip, E. E. M. Kahar, N. Muhammad, N. Abdullah i H. Basri. "Solvent used in extraction process of agarwood: a systematic review". Food Research 4, nr 3 (4.01.2020): 731–37. http://dx.doi.org/10.26656/fr.2017.4(3).333.
Streszczenie:
The method of extraction of Agarwood is usually dependent on the purpose of the extract. This systematic review aims to look at the number of studies that use different types of solvents in the process of extraction. There are 3 types of solvents commonly used in the extraction of agarwood essential oils namely methanol, ethanol and water. Each solvent produces different extracts in terms of quantity and quality of the final product. However, there is controversy over the use of solvents as it may cause a cytotoxic effect on the user. Another common type of solvent is water. Although water is a cheap solvent and relatively safe, aqueous extracts have more impurities that make isolating the desired compound difficult. After the extraction process, the crude extract was fractionated into the desired compounds and this technique is widely applied, especially in the whole process of extraction of the agarwood. In conclusion, extraction solvents have certain advantages and disadvantages, and this is one of the reasons why this extraction method depends on the purpose of using the final product such as agarwood essential oil.
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Schuster, Anja, Nina Ortmayr, Gertie Janneke Oostingh i Bettina Stelzhammer. "Compounds extracted from larch, birch bark, Douglas fir, and alder woods with four different solvents: Effects on five skin-related microbes". BioResources 15, nr 2 (25.03.2020): 3368–81. http://dx.doi.org/10.15376/biores.15.2.3368-3381.
Streszczenie:
Wood is an important natural resource, and the extracts of specific wood species might have growth-inhibiting effects on certain microbes. This property can be used in the pharmaceutical industry to develop phytochemical-based medicine to treat skin infections. Thus far, methanol, intrinsically toxic, has been the main solvent used for extraction of soluble wood compounds. In this study, the focus was placed on biocompatible solvents, including dimethyl sulfoxide, distilled water, and glycerin, in addition to methanol used to extract compounds from larch, birch bark, Douglas fir, and alder wood sawdust. Microbial growth was tested on four different bacterial strains and one type of fungi representing species that can affect the skin. The results revealed intrinsic toxicity of biocompatible solvents at low concentrations as well as an additive or synergistic effect of wood extracts. In particular, larch and birch extracts strongly decreased microbial growth. In addition, interference of the extract color on the measurements was observed, which must be taken into account to ensure correct analysis of the data. In conclusion, biocompatible solvents in conjunction with larch and birch extracts exhibited antimicrobial effects. The importance of solvent toxicity and background staining were highlighted to determine potential antimicrobial effects.
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Geetha, Sethupandian, Kokkaiah Irulandi i Palanichamy Mehalingam. "EVALUATION OF ANTIOXIDANT AND FREE RADICAL SCAVENGING ACTIVITIES OF DIFFERENT SOLVENT EXTRACTS OF LEAVES OF PIPER UMBELLATUM". Asian Journal of Pharmaceutical and Clinical Research 10, nr 2 (1.02.2017): 274. http://dx.doi.org/10.22159/ajpcr.2017.v10i2.15570.
Streszczenie:
Objective: This study was designed to determine the Total phenol, flavonoid content, antioxidant and free radical scavenging properties of different solvent extracts of Piper umbellatum. Methods: Different solvent extracts evaluated with DPPH radical scavenging activity and Reducing power activity.Results: The presence of phenol and flavonoid showed highly in the methanol extracts than ethyl acetate and acetone extracts. All the extracts have various level of antioxidant activity. Methanol solvent extract have good extraction and show significant antioxidant activity. The effect of reducing power of methanol extract revealed good antioxidant activity compare with other tested extracts.Conclusion: On the basis of the above results we concluded that methanol extract of Piper umbellatum whole plant extracts shows significant antioxidant activity than ethyl acetate and acetone extracts.Keywords: Piper umbellatum, Antioxidant, DPPH, FRAP assay, Polar, Non polar solvents
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Karunakaran, Thiruventhan, Yong Sean Goh, Rameshkumar Santhanam, Vikneswaran Murugaiyah, Mohamad Hafizi Abu Bakar i Surash Ramanathan. "RP-HPLC-DAD Analysis of Mitragynine Content in Mitragyna speciosa Korth. (Ketum) Leaf Extracts Prepared Using Ultrasound Assisted Extraction Technique and Their Cytotoxicity". Separations 9, nr 11 (3.11.2022): 345. http://dx.doi.org/10.3390/separations9110345.
Streszczenie:
Mitragynine and its congeners are one of the major phytoconstituents present in Mitragyna speciosa Korth. (ketum) leaves and a well-known factor that contributes to ketum’s pharmacological activities. This study describes the usage of a green extraction method to yield botanical leaf extracts of ketum. The leaf extracts were assessed for mitragynine content, total phenolic and flavonoid content, and cytotoxicities. The Ultrasound Assisted Extraction (UAE) method showed a varying dry yield of the extracts (0.22–1.92 g) that were obtained with solvents of variable polarities. However, the mitragynine content was consistent among the organic solvent extracts (7.22–9.40%). This method calls for a minimal extraction solvent volume (solid to solvent ratio, 1:30) and a shorter extraction period (20 min). Of the solvents tested, the methanolic extract showed the highest content of total phenolic (419.50 ± 2.50 GAE mg/g) and flavonoids (177.33 ± 3.00 QE mg/g). The extract was nontoxic towards kidney (HEK-293) and Chang liver (HeLa) cell lines. Analysis via UHPLC-ESI-QTOF-MS/MS made it possible to identify mitragynine congeners, such as mitragynine, paynantheine, and speciociliatine, in the leaves extract. In conclusion, the UAE method using methanol as the extraction solvent provides a noncytotoxic ketum botanical extract for future preclinical and clinical studies.
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Mokhtar, Siti Umairah. "Comparison of total phenolic and flavonoids contents in Malaysian propolis extract with two different extraction solvents". International Journal of Engineering Technology and Sciences 6, nr 2 (29.12.2019): 1–11. http://dx.doi.org/10.15282/ijets.v6i2.2577.
Streszczenie:
This study is aimed to prepare propolis extracts by using two different solvents which are ethanol and water via maceration method and to evaluate the total phenolic and flavonoid components of the extract. Optimization of the extraction process was done by using different solvents and sample-to-solvent ratio. The ethanolic and water extracts were analysed for the determination of Total Phenolic Content (TPC) and Total Flavonoid Content (TFC) by using Folin-Ciocalteu colorimetric method and Aluminimum chloride method, respectively. Based on sample-to-solvent ratio, it showed that 1:10 gave the highest percentage yield compared to other ratio for both solvents. Ethanolic extract resulted contains high phenolic and flavonoids content compared to water extract. The result showed that sample-to-solvent ratio 1:5 gave highest TPC and TFC in ethanolic extract which are 29.09 and 7.75 mg GAE/g, respectively. In conclusion, this study revealed that ethanol is the best extraction solvent to be used for propolis extraction compared to water. It is also demonstrated that higher volume of solvent does not leads to high values of TPC and TFC. The optimum extraction parameters and conditions are necessary to be obtained in order to extract high TPC and TFC.
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Tzani, Andromachi, Ioanna Pitterou, Foteini Divani, Thalia Tsiaka, Georgios Sotiroudis, Panagiotis Zoumpoulakis i Anastasia Detsi. "Green Extraction of Greek Propolis Using Natural Deep Eutectic Solvents (NADES) and Incorporation of the NADES-Extracts in Cosmetic Formulation". Sustainable Chemistry 4, nr 1 (26.12.2022): 8–25. http://dx.doi.org/10.3390/suschem4010002.
Streszczenie:
In this work, a greener approach for the extraction of Greek propolis using ultrasound-assisted extraction method in combination with Natural Deep Eutectic Solvents (NADES) is presented. Propolis is a natural material of outmost interest as it possesses various biological and pharmacological activities and is therefore used for the manufacturing of extracts useful to various fields, such as pharmaceutics, cosmetics etc. Herein, five NADES were task-specifically selected as appropriate extraction solvents since they provide important assets to the final NADES-extracts, comparing to the conventionally used organic solvents. The screening study of the prepared solvents indicated the NADES L-proline/D,L-Lactic acid as the most effective medium for the raw propolis extraction due to the extract’s high total phenolic content as well as its’ significantly higher antioxidant activity. Then, the extraction using the selected NADES, was optimized by performing Experimental Design to study the effect of extraction time, propolis-to-solvent ratio and the %NADES content in the NADES-water system. All the extracts were characterized regarding their antioxidant activity and total phenolic content. The optimum NADES-extract as well as an extract derived by extraction using a conventional hydroethanolic solution were further characterized by performing LC/MS/MS analysis. The results showed that the NADES-extracts composition was similar or superior to the hydroethanolic extracts regarding the presence of valuable phytochemicals such as apigenin, naringenin etc. A disadvantage that is usually mentioned in the literature regarding the extractions using NADES is that the extracted bioactive compounds cannot be easily separated from the NADES in order to obtain dry extracts. However, this drawback can be converted to an asset as the task-specifically designed NADES that are used in this study add value to the end product and the optimum as-obtained NADES-extract has been successfully incorporated in a cosmetic cream formulation. In this work, The antioxidant activity and organoleptic characteristics of the cream formulation were also determined.
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Udaya Prakash N K, Sriraman V, Devika V, Peneena V, Sripriya N, Bhuvaneswari S i Sampathkumar B. "Comparative studies on phytochemistry, antioxidant and antibacterial activity of direct and sequential extracts of chromolaena odorata leaves". International Journal of Research in Pharmaceutical Sciences 10, nr 2 (15.04.2019): 914–21. http://dx.doi.org/10.26452/ijrps.v10i2.275.
Streszczenie:
Phytochemistry, antioxidant and antibacterial activities of different solvent extracts of Chromolaena odorata leaves obtained by direct and sequential extraction were compared in this study. Antibacterial evaluation of the extracts was performed through a disc diffusion method. The results revealed that the solvents, Petroleum ether and Ethyl acetate showed the presence of a majority of the phytochemicals, Chloroform extract yielded maximum TPC and TAA and ethyl acetate yielded higher TFC when compared to other solvents. Ethanol and chloroform extracts showed lower concentrations of IC50 against DPPH and NO radicals respectively. Acetone recorded the maximum zone of inhibition against Staphylococcus aureus and Pseudomonas aeruginosa; ethyl acetate against Bacillus subtilis and Chloroform against Streptococcus mutans. Among the solvents studied for phytochemical content and bioactivities, ethanol showed a higher level of phytochemical extraction and better bioactivities. As a direct solvent extraction of C. odorata showed better efficiency when compared with sequential extraction, the study strongly recommends the use of a direct extraction method.
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Thuanthong, Arthittaya, Jaran Patchimpet, Wonnop Visessanguan, Jarurat Panyo, Soottawat Benjakul, Yi Zhang i Sappasith Klomklao. "Antioxidant properties of sacha inchi (Plukenetia volubilis) shell extracts as affected by solvents used for prior decolorization". ASEAN Journal of Scientific and Technological Reports 24, nr 3 (25.12.2021): 1–8. http://dx.doi.org/10.55164/ajstr.v24i3.243570.
Streszczenie:
Sacha inchi (Plukenetia volubilis) shell is a potential source of phenolics with an-tioxidative activity and its extract can be used to prevent lipid oxidation in some food matrices. However, the sacha inchi extract has been fully exploited due to the dark brown colour properties associated with pigments. Thus, de-colourization of sacha inchi shells before extraction using solvents could be a means to bring about the extract with a lighter colour, which could be applied in foods without constraints. The effects of different solvents used for decolour-ization in sacha inchi (Plukenetia volubilis) shell powder on antioxidant proper-ties were investigated. The solvents used were methanol, acetone, chloroform and propanol. The ethanolic extracts' total phenolic content (TPC) and total flavonoid content (TFC) decreased when solvents were employed for prior de-colourization. Among all solvents, the ethanolic extracts from sacha inchi shell powder decolourized using chloroform (CHE) showed the highest TPC (9.94 mg GAE/g dry extract) and TFC (7.20 mg CE/g dry extract). Also, extracts from chloroform decolourized shell powder had the highest antioxidant activities (2,410.01, 111.60 and 4.58 µmol TE/g dry extract for 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scaveng-ing activities, ferric reducing antioxidant power (FRAP), respectively, and 0.52 mmol EDTA /g dry extract for metal chelating assay) compared to other ex-tracts. Therefore, chloroform was the appropriate solvent for decolourization, and the resulting extract had higher antioxidant properties than others.
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V. Le, Anh, Sophie E. Parks, Minh H. Nguyen i Paul D. Roach. "Improving the Vanillin-Sulphuric Acid Method for Quantifying Total Saponins". Technologies 6, nr 3 (6.09.2018): 84. http://dx.doi.org/10.3390/technologies6030084.
Streszczenie:
The colorimetric assay used for saponin quantification in plant extracts is subject to interference by common solvents used to extract the saponins from plant materials. Therefore, the degree of interference of ten common solvents was investigated. It was found that the presence of acetone, methanol and n-butanol in the reaction solution caused an intense darkening of the reaction solution in the absence of saponins, which likely could lead to erroneous saponin content values. Using aescin to construct standard curves with different solvents—such as water, ethanol, and methanol— also showed significant differences in the standard curves obtained, which led to different values when they were applied to quantify the saponin content of an ethanol extract from dried and powdered Gac (Momordica cochinchinensis Spreng) seed kernels. To improve the method, a solvent evaporation step was added prior to the colorisation reaction to prevent undesired solvent interference during the reaction step. Using this modified protocol for the aescin standard curve and the Gac seed kernel extract eliminated any solvent interference. Thus, this improved protocol is recommended for the quantification of the saponin content of plant extracts irrespective of which extraction solvent is used.
Rozprawy doktorskie na temat "Solvents extracts":
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Rix, Catherine S. "Detecting life on Mars and the life marker chip : antibody assays for detecting organic molecules in liquid extracts of Martian samples". Thesis, Cranfield University, 2012. http://dspace.lib.cranfield.ac.uk/handle/1826/7250.
Streszczenie:
The Life Marker Chip instrument, which has been selected to fly as part of the 2018 ExoMars rover mission payload, aims to detect up to 25 organic molecules in martian rocks and regolith, as markers of extant life, extinct life, meteoritic in-fall and spacecraft contamination. Martian samples will be extracted with a solvent and the resulting liquid extracts will be analysed using multiplexed microarray-format immunoassays. The LMC is under development by an international consortium led by the University of Leicester and the work described within this thesis was carried out at Cranfield University as part of the consortium’s broader program of work preparing the LMC instrument for flight in 2018. Within this thesis four specific areas of LMC instrument development are addressed: the investigation of immunoassay compatible liquid extraction solvents, the study of likely interactions of martian sample matrix with immunoassays, the development of antibodies for the detection of markers of extinct life and demonstration of solvent extraction and immunoassay detection in a flight representative format. Cont/d.
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Palu, Doreen. "Etude de la composition chimique d’extraits d’Ilex aquifolium Linné et de Calicotome villosa (Poiret) Link de Corse par RMN du carbone-13". Electronic Thesis or Diss., Corte, 2022. http://www.theses.fr/2022CORT0018.
Streszczenie:
L’objectif de ce travail de thèse était de déterminer la composition chimique d’extraits de plantes de Corse encore peu ou pas étudiées et susceptibles d’avoir des activités biologiques valorisables. Cette étude a été menée en mettant en œuvre la méthodologie d’analyse des mélanges complexes par RMN 13C, développée depuis une trentaine d’années par l’équipe « Chimie et Biomasse » de l’UMR CNRS 6134 Sciences pour l’Environnement de l’université de Corse. Dans une première partie, nous avons étudié la composition chimique d’extraits de houx commun (Ilex aquifolium L.). Deux extraits de feuilles (obtenus à l’hexane et au dichlorométhane) ont chacun subi deux fractionnements successifs par chromatographie sur colonne ouverte de silice. L’analyse par RMN 13C (CPG(Ir) et CPG-SM également dans certains cas) des extraits bruts et des fractions de chromatographie a permis l’identification de onze triterpènes dont l’α-amyrine et la β-amyrine et certains de leurs esters. Parallèlement, deux acides triterpéniques d’intérêt (acide ursolique et acide oléanolique) ont été quantifiés par RMN 1H au sein de l’extrait brut au dichlorométhane via une méthode rapide mise au point et validée (justesse, linéarité, précision des mesures). Ces deux composés représentent respectivement 55,3% et 20,8% de l’extrait. Nous avons également réalisé, en collaboration avec l’équipe « Biochimie et Biologie Moléculaire du Végétal » de l’université de Corse, des tests antimicrobiens sur les extraits et certaines fractions de chromatographie. Les deux acides triterpéniques précédemment cités ont montré une activité antimicrobienne comparable à celle du chloramphénicol (antibiotique de référence) vis-à-vis de trois bactéries à Gram positif, Staphylococcus aureus, Staphylococcus epidermidis et Bacillus cereus (CMI = 4 et 8 mg.L-1 vs. 2 et 4 mg.L-1). Par ailleurs, nous avons préparé des extraits de baies de houx en utilisant différents solvants : hexane, dichlorométhane, dichlorométhane/acétate d’éthyle (50/50, v/v). Les deux derniers extraits (dichlorométhane et dichlorométhane/acétate d’éthyle) ont subi des fractionnements successifs et l’étude des spectres RMN 13C des extraits bruts et des fractions de chromatographie a permis d’identifier neuf triterpènes (précédemment identifiés), cinq dérivés phénoliques, six monosaccharides ainsi que quatre lactones (la ménisdaurilide, l’aquilégiolide, la 7-épi-griffonilide et la dasycarponilide) non encore répertoriées dans le houx commun. Dans une seconde partie, nous avons étudié la composition chimique d’extraits de fleurs et de racine de Calicotome villosa (Poir.) Link. Les extraits de fleurs obtenus au dichlorométhane et à l’acétate d’éthyle ont été soumis à des chromatographies successives. L’analyse par RMN 13C des extraits bruts et des fractions de chromatographie a permis l’identification de trois flavonoïdes, cinq dérivés glucosylés de flavonoïdes et quatre phénylpropanoïdes. Dans cette partie, nous nous sommes également intéressés à la composition chimique d’un extrait méthanolique de racine de C. villosa qui n’a fait l’objet d’aucune étude de ce type au préalable. Cet extrait a été soumis à plusieurs fractionnements successifs et dix-huit composés, notamment des stérols, des flavonoïdes, un polyphénol et des ptérocarpanes ont été identifiés par RMN 13CThe aim of this work was to determine chemical composition of wild growing corsican understudied plant species, with potential biological activities. This study was realized using the computerized NMR method developed over the past thirty years by the University of Corsica “Chimie et Biomasse” group, UMR CNRS “Sciences Pour l’environnement”. Identified secondary metabolites were then undertaken to evaluate their antimicrobial properties. As part of this study, we selected on the first place commun holly (Ilex aquifolium L.). After two successive column chromatography, hexane and dichloromethane leaves crude extracts and all chromatography fractions were analyzed by 13C NMR (GC(RI) and GC-MS sometimes) to allow the identification of eleven triterpens and α- and β-amyrin esters. Among identified compounds, ursolic acid and oleanolic acid were also quantified by 1H NMR in the dichloromethane crude extract using a reliable method developped and validated (accuracy, linearity precision of measurements). Ursolic acid accounted for 55.3% of the extract, followed by oleanolic acid, 20.8%. Evaluation of previous identified compounds antimicrobial activities has been performed in collaboration with « Biochimie et Biologie Moléculaire du Végétal » group (University of Corsica). Triterpen acids and chloramphenicol (reference antibiotic) displayed similar antibacterial activities against three Gram-positive bacteria, Staphylococcus aureus, Staphylococcus epidermidis and Bacillus cereus (MIC = 4 and 8 mg.L-1 vs. 2 and 4 mg.L-1). Moreover, dichloromethane and dichloromethane/ethyl acetate (50/50, v/v) berries extracts were submitted to successive column chromatography. Crude extracts and chromatography fractions 13C NMR spectra revealed presence of nine triterpens previously identidied, five phenolics derivatives, six monosaccharides and four lactones (menisdaurilide, aquilegiolide, dasycarponilide and 7-epi-griffonilide) were first time identified in berries holly extracts. On the second place, we determined chemical compositions of Calicotome villosa (Poir.) Link flowers and root extracts. 13C NMR analysis of dichloromethane and ethyl acetate flowers extracts and their chromatography fractions, allowed the identification of three flavonoids, five glycosyl flavonoids and four phenylpropanoids. We also studied chemical composition of a methanol root extract which has never been submitted to any chemical composition study. After successive column chromatography, eighteen compounds were identified by 13C NMR including sterols, flavonoids, a polyphenol and pterocarpans
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Coppa, Carolina Fernanda Sengling Cebin. "Extração de oleuropeína de folhas de oliva com solvente hidroalcoólico e efeito dos extratos sobre a estabilidade oxidativa de óleos vegetais". Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/74/74132/tde-01062016-114325/.
Streszczenie:
A oleuropeína é o composto fenólico mais abundante presente nas folhas da oliveira, sendo que muitos estudos vêm demonstrando que este composto apresenta importantes propriedades antimicrobiana, antioxidante, anti-inflamatória, entre outras, surgindo o interesse em estudos de métodos para sua extração e aplicação em produtos na área alimentícia, cosmética e farmacêutica. O objetivo deste estudo foi a extração da oleuropeína à partir de folhas de oliva, utilizando solvente não tóxico, para posterior aplicação dos extratos em óleos vegetais a fim de se verificar seu efeito sobre a estabilidade oxidativa dos mesmos. O solvente selecionado para o estudo foi uma mistura de etanol e água (70:30, em massa, condição obtida através de um trabalho prévio), na presença de 1 % de ácido acético. Em uma primeira etapa, foram realizados experimentos de extração utilizando-se as técnicas de maceração (tipo I) e ultrassom (tipo II), em diferentes condições de temperatura (20, 30, 40, 50 e 60°C). Em uma segunda etapa, através de experimentos com maceração à temperatura ambiente, estudou-se o efeito da razão folhas:solvente (1:8, 1:6 e 1:3) e a influência da presença de ácido acético sobre o processo de extração (tipo III). Por fim, realizando-se a maceração na presença de ácido acético, temperatura ambiente e proporção folhas: solvente igual a 1:3, realizaram-se extrações sequenciadas a partir de uma mesma matéria-prima (tipo IV). Os resultados desses experimentos foram expressos em rendimento de oleuropeína (RO), teor de oleuropeína nos extratos (TO) e rendimento global (RG). Analisando-se os experimentos I e II, verificou-se que a temperatura não exerceu influência significativa sobre as respostas RO, TO e RG. Além disso, verificou-se que os valores das respostas para os experimentos com a maceração foram um pouco maiores do que os valores obtidos para as extrações com o auxílio do ultrassom. Nos experimentos tipo III, em linhas gerais, observou-se a influência positiva da presença do ácido acético sobre as respostas estudadas. Verificou-se também que, na presença de ácido, o aumento da quantidade de solvente na extração conduz ao aumento de RO e RG, e à diminuição de TO. Através do experimento tipo IV, constatou-se que mesmo após quatro extrações sequenciadas, ainda não foi possível esgotar a oleuropeína da matéria-prima. Após a obtenção de todos os extratos hidroalcoólicos, selecionou-se um contendo aproximadamente 19 % de oleuropeína para o estudo da estabilidade oxidativa em óleos vegetais (oliva e girassol) utilizando o método Rancimat. A presença de extrato aumentou em 3 horas o tempo de indução do azeite de oliva extra-virgem, e em 2 horas o tempo de indução do azeite de oliva comum. Os óleos de girassol bruto e refinado não apresentaram melhora na estabilidade oxidativa quando adicionados dos extratos. Foram realizados também testes de estabilidade oxidativa através da adição direta de folhas de oliva em pó nos azeites de oliva extra-virgem e comum. Para o azeite extra-virgem, a adição das folhas não proporcionou melhora da estabilidade oxidativa, porém para o azeite comum, houve um aumento de mais de 2 horas no tempo de indução.Os resultados apresentados neste trabalho demonstraram que é possível obter extratos contendo teores significativos de oleuropeína utilizando-se um solvente renovável. Além disso, constatou-se que os mesmos podem ser utilizados como um antioxidante natural em azeite de oliva, melhorando sua estabilidade oxidativa.Oleuropein is the most abundant phenolic compound present in the leaves of the olive tree, and many studies have shown that this compound has significant antimicrobial properties, antioxidant, anti-inflammatory, among others, emerging interest in studies of methods for extraction and use in products in the food industry, cosmetics and pharmaceuticals. The aim of this study was the extraction of oleuropein from the olive leaf, using non-toxic solvent, for further application of the extracts in vegetable oils in order to check its effect on their oxidative stability. The solvent selected for the study was a mixture of ethanol and water (70:30, % mass, condition obtained from a previous study), in the presence of 1 % acetic acid. In a first step, extraction experiments were conducted using maceration (type I) and ultrasound (type II) under different temperature conditions (20, 30, 40, 50 and 60 ° C). In a second step, through experiments with maceration at room temperature, the effect of the ratio olive leaves:solvent (1:8, 1:6 and 1:3) and the influence of the presence of acetic acid on the process of extraction (type III) was studied. Finally, using maceration in the presence of acetic acid at room temperature and proportion olive leaves:solvent of 1:3, sequencial extractions from the same raw material (type IV) were performed. The results of these experiments were expressed in oleuropein yield (RO), oleuropein content in extracts (TO) and global yield (RG). Analyzing the experiments I and II, it was found that the temperature did not have significant influence on the RO, TO and RG values. Furthermore, it was found the response values for the experiments with maceration was somewhat higher than values obtained for extractions using ultrasound. In type III trials, in general, a positive influence of the presence of acetic acid in the studied answers were observed. It was also found that in the presence of acid, higher amount of solvent leads to an increase of RO and RG values, and a decrease of TO value. Through the experiment type IV, it was found that even after four sequential extractions, it was not possible to exhaust oleuropein raw material. After obtaining all the hydroalcoholic extracts, na extract contanining approximately 19 % of oleuropein was selected for the study of oxidative stability of vegetable oils (olive and sunflower oil), using the Rancimat method. The presence of extract increased in 3 hours the induction time of extra-virgin olive oil, and in 2 hours the induction time of common olive oil. Crude and refined sunflower oils showed no improvement in the oxidative stability when added to the extracts. Oxidative stability tests were also performed by direct addition of olive leaf powder in extra virgin and common olive oil. For extra virgin olive oil, the addition of the powder leaves did not improve the oxidative stability, but for the common oil, an increase of more than 2 hours in induction time was observed. Results demonstrated that it is possible to obtain extracts containing significant concentrations of oleuropein using a renewable solvent. Furthermore, it was found that it can be used as a natural antioxidant in olive oil, improving its oxidative stability.
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Tófoli, Rodolfo José [UNESP]. "Avaliação de biocompostos e composição mineral de extratos provenientes de duas macroalgas lóticas do estado de São Paulo". Universidade Estadual Paulista (UNESP), 2017. http://hdl.handle.net/11449/150494.
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No Brasil, há uma grande biodiversidade de espécies de algas lóticas, Dentre as mais conhecida, encontradas em rios e riachos da região sudeste do estado de São Paulo destaca-se a Oedogonium sp. e a Nitella microcarpa var. wrightii., dois gêneros de algas verdes. Entretanto, estudos de caracterização química de extratos destas algas ainda são inexistentes. Por esse motivo destaca-se a importância deste trabalho, o qual encontra-se subdivido em dois estudos. O primeiro teve por objetivo avaliar e quantificar compostos fenólicos e capacidade antioxidade de extratos de diferentes solventes da alga Oedogonium sp. Utilizou-se um delineamento experimental de mistura para determinar a influência dos solventes e verificou-se qual desses apresentou melhor rendimento na extração desses compostos da alga em pó. O segundo estudo teve por objetivo realizar a caracterização de duas macroalgas verdes: Nitella microcarpa var. wrightii, e Oedogonium sp., através da obtenção de um extrato, com o melhor sistema de solventes obtidos no primeiro estudo. Desta forma, foi possível quantificar quanto a presença de minerais, flavonoides, umidade, carotenoides, compostos fenólicos e capacidade antioxidante. No primeiro estudo, os resultados sugeriram que a mistura acetona-etanol apresentou melhor rendimento de extração tanto para compostos fenólicos como à capacidade antioxidante. No segundo estudo, a alga Oedogonium sp. destacou-se por apresentar uma grande quantidade de carotenoides totais. Já a espécie Nitella microcarpa var. wrightii, obteve altos valores de minerais.
In Brazil, there is a great biodiversity of lotic algae species. Among the most well known species found in rivers and streams in the southeast region of the state of São Paulo is Oedogonium sp. and Nitella microcarpa var. Wrightii., Two genus of green algae. However, studies of chemical characterization of extracts of these algae are still non existent. For this reason the importance of this work is highlighted, which is subdivided in two studies. The first one had the objective to evaluate and quantify phenolic compounds and antioxidant capacity of extracts of different solvents of the algae Oedogonium sp. An experimental design of the mixture was used to determine the influence of the solvents and it was verified which of them presented better yield in the extraction of these compounds from the powdered seaweed. The second study aimed to characterize two green macroalgae: Nitella microcarpa var. Wrightii, and Oedogonium sp., by obtaining an extract, with the best solvent system obtained in the first study. In this way, it was possible to quantify the presence of minerals, flavonoids, moisture, carotenoids, phenolic compounds and antioxidant capacity. In the first study, the results suggested that the acetone-ethanol-water mixture had a better extraction yield for both phenolic compounds and antioxidant capacity. In the second study, the alga Oedogonium sp. was characterized by a large amount of total carotenoids. The other alga, of the species Nitella microcarpa var. Wrightii, has achieved high mineral values.
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Ceschini, Valmir Carneiro. "Potencial antífungico de extratos de folhas de Eucalyptus staigeriana F. Muell. sobre Aspergillus flavus". Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/11/11141/tde-22112011-135925/.
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O objetivo deste trabalho foi avaliar o potencial antifúngico contra o fungo Aspergillus flavus, dos extratos de folhas de Eucalyptus staigeriana F. Muell., preparados a partir de folhas frescas, liofilizadas e secas ao ambiente, sob diferentes tempos de extração e por diferentes solventes extratores, tais como metanol, etanol e água a temperatura ambiente e água a 60ºC. Para mensurar o potencial antifúngico foi utilizada a técnica de poisoned food em meio BDA e o crescimento radial fúngico foi avaliado por seis dias. O percentual de inibição foi avaliado comparando-se as medidas do diâmetro radial de crescimento fúngico dos extratos com as placas controle contendo apenas os solventes. Como controle positivo foi utilizado o óleo essencial de E. staigeriana. Os extratos metanólicos apresentaram o melhor potencial antifúngico, seguido pelos extratos etanólicos e aquosos. A utilização das folhas frescas mostrou-se a melhor forma de preparação e não houve diferença significativa entre os tempos de extração 1h e 24h, indicando como processamento mais viável a extração em 1h. A Concentração Inibitória Mínima (MIC) foi mensurada para o extrato de melhor desempenho pela técnica de micropoços, aonde o crescimento fúngico foi monitorado por fluorescência derivada da reação da esterase fúngica com o diacetado de fluorescina. E o extrato que obteve o melhor resultado foi o extrato metanólico, com 1h de extração, a partir de folhas liofilizadas de E. staigeriana, e sua MIC foi de 26,75 L/mL, enquanto a do seu óleo essencial foi de 12,5 L/mL, demonstrando a eficiência relativa da extração com solventes extratores e sua praticidade e operacionalidade, quando se comparam com a extração de óleos essenciais.This study aimed to evaluate the antifungal potential of Eucalyptus staigeriana F. Muell. leaf extracts against Aspergillus flavus. The extracts were prepared using fresh, lyophilized, and air-dried leaves, different extraction times, and different solvents, such as methanol, ethanol, water at room temperature, and water at 60ºC. To measure the antifungal potential, the poisoned food technique was used in PDA medium, and the radial growth of the fungus was evaluated for six days. The percentage of inhibition was assessed by comparing the measurements of the radial growth diameter of the fungus in the extracts with the control plates containing only the solvents. The essential oil of E. staigeriana was used as a positive control. The methanolic extracts presented the best antifungal potential, followed by the ethanolic and aqueous extracts. The use of fresh leaves was the best type of preparation and no statistically significant difference between 1-h and 24-h solvent extraction was found, indicating the 1-h extraction process as the most feasible. The extract presenting the best performance using the microwell technique had the minimum inhibitory concentration (MIC) measured, and the fungal growth was monitored by fluorescence derived from the fungal esterase reaction with fluorescein diacetate. The extract that achieved the best result the methanolic extract, with 1-h extraction from lyophilized leaves of E. staigeriana, and the MIC was 26.75 L/mL, while the essential oil was 12.5 L/mL, demonstrating the relative efficiency of the solvent extraction and its practicality and easy implementation when compared with the extraction of essential oils.
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Gomes, Anabele Stefânia. "Atividade fitotóxica de extratos foliares de Pouteria torta (Mart.) Radlk". reponame:Repositório Institucional da UnB, 2013. http://repositorio.unb.br/handle/10482/14735.
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Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Biológicas, Departamento de Botânica, Programa de Pós-Graduação em Botânica, 2013.Submitted by Alaíde Gonçalves dos Santos (alaide@unb.br) on 2013-11-27T14:34:04Z No. of bitstreams: 1 2012_AnabeleStefaniaGomes.pdf: 1370930 bytes, checksum: 4d5d493106f69e8466f2278a7446d488 (MD5)
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Muitos metabólitos secundários podem ser sintetizados desde os primeiros estágios da planta, no entanto outros podem ter sua produção desencadeada ou aumentada em resposta a algum estímulo ambiental, o que pode afetar seu potencial fitotóxico. O método de extração e o tipo de solvente utilizado para tal podem interferir na estrutura de produtos e na quantidade a ser extraída. O objetivo desse trabalho foi avaliar o potencial fitotóxico de extratos aquosos de folhas de P. torta coletadas na estação chuvosa e na estação seca no Cerrado, e obtidos por extração a quente e a frio, nas espécies alvo Sesamum indicum (gergelim) e Urochloa decumbens (braquiária). Ainda, comparar a atividade dos extratos aquosos com extratos obtidos por acetato de etila. Os extratos foram testados em cinco concentrações, 200, 400, 800, 1600 e 3200 ppm. Foram realizados experimentos de germinação e crescimento inicial em placa de petri que foram mantidas em câmara de germinação por sete dias, a 30ºC, com fotoperíodo de 12h. Não houve diferença na atividade em relação à época de coleta ou ao método de extração. Em relação ao extrato obtido por acetato de etila, a extração aquosa mostrou-se mais indicada para obtenção de fitoquímicos na espécie estudada, por ter maior efeito inibitório sob as espécies-alvo, além de ter baixo custo. A germinabilidade e o tempo médio de germinação não foram alterados em nenhuma das espécies, no entanto, o crescimento inicial foi inibido. O crescimento radicular foi mais sensível aos efeitos dos fitoquímicos que o crescimento aéreo. O gergelim mostrou-se mais sensível aos tratamentos do que a braquiária. ______________________________________________________________________________________ ABSTRACT
Many secondary metabolites can be synthesized since the earliest stages of plants life, however, others may have their production initiated or increased in response to an environmental stress, which can affect their phytotoxic potential. The method of extraction and the solvent used may interfere with the structure of products and quantity to be extracted. The aim of this study is to evaluate phytotoxic potential of aqueous extracts from leaves of P. Torta, collected during the rainy and the dry season in Cerrado, obtained by hot and cold extractions, using as the target species Sesamum indicum and Urochloa decumbens. Also, to compare the activity of aqueous extracts with the extracts obtained by ethyl acetate. The extracts were tested at five different concentrations: 200, 400, 800, 1600 and 3200 ppm. Germination and early growth experiments were tested in Petri dish, which were kept in growth chamber for seven days, at 30°C, with a 12h photoperiod .There was no difference in the activity concerning to time of collection or method of extraction. Regarding the extract obtained by ethyl acetate, the aqueous extraction was more suitable for obtaining phytochemicals from the studied specie, because of greater inhibitory effect on target species and low cost. Germinability and the mean time to germination were not altered in any target species, however, early growth was inhibited. Root growth was more sensitive to effects of phytochemical than to aerial growth. The sesame was more sensitive to the treatments than brachiaria.
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Zamil, Raya. "Recycling Cathode of Lithium-Ion Battery by Using Deep Eutectic Solvents to Extract Cobalt". Thesis, Umeå universitet, Kemiska institutionen, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-173089.
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Zancan, Kelly Cristine. "Obtenção de extrato de gengibre (Zingiber officinale Roscoe) com dioxido de carbono supercritico e co-solventes : um estudo da atividade biologica dos extratos". [s.n.], 2001. http://repositorio.unicamp.br/jspui/handle/REPOSIP/254874.
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Orientador: Maria Angela de Almeida MeirelesDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: o gengibre e seus produtos tais como o óleo essencial e oleoresina são internacionalmente comercializados para uso nas indústrias de alimentose farmacêuticas.O óleo essencial possui os compostos mais voláteis responsáveis pelo aroma característico do gengibre e a oleoresina contem além destes, substâncias classificadas como pungentes. Algumas destas substâncias pungentes agem como importantes antioxidantes. Atualmente, antioxidante obtidos a partir de fontes naturais são associados a benefícios para saúde humana, uma vez que os radicais livres estão relacionados com doenças do coração, malária, AIDS, câncer, neurodegenerativas entre outras. Devido a isso toma-se muito importante o estudo de novos antioxidantes. O uso da extração supercritica tem crescido muito nos últimos anos, entretanto ainda é necessária a obtenção de um número considerável de informações experimentais para que a construção de plantas indústriais deste tipo de processo aconteça. Neste trabalho os efeitos da temperatura (25 e 35°C), pressão (200 e 250 bar) e o uso de co-solventes (etanol e isopropanol, ambos ai, 17% (mim)) sobre o rendimento total e a cinética de extração da oleoresina de gengibre foram estudados. O equipamento utilizado consistiu de um extrator de leito fixo com diâmetro de 2,83x10.2m e comprimento de 0,375 m. Os ensaios foram realizados com vazão média de CO2de 5,83xlO-5kg/s. Os experimentos tiveram 7 horas de duração. A duração do periodo de taxa constante de extração variou de 1,3 a 2,7 horas e os rendimentos ficaram na faixa de 1,93% a 2,65%. A identificação das substâncias presentes na oleoresina foi feita através de CGIEM. Os extratos de gengibre analisados mostraram-se antioxidantes eficazes, possuíram ação anticancerígenas para algumas linhagens de câncer e inibiram o crescimento de algumas bactérias aqui estudadas. A espectrofotometria mostrou-se inadequada para a quantificação dos gingeróis e shogaóis. Os extratos do período de taxa constante e de taxa decrescente de extração apresentaram monoterpenos, sesquiterpenos, gingeróis e shogaóis em sua composição, enquanto o período difusional mostrou principalmente gingeróis e shogaóis.
Abstract: Ginger and ginger products such as essencial oil and oleoresin are internationally comercialized for use in food and pharmaceutical processing. The essential oil posses the volatile compounds responsible for the characterist ginger flavor and the oleoresin contains also substances classified as pungent. Some of these pungent substances act as important antioxidant agents. Today, antioxidants from natural resources are associated with health benefits since oxygenated compounds are related to a positive action against heart deseases, malaria, neurodegenerative, AIDS, cancer. The use od SCFE in the last years has increased steadily but yet a number of experimental information needed for process desing is still lacking. In this work the effects of temperature ( 25 and 35°C), pressure (200 e 250 bar), and the use of co-colvent (ethanol and isopropanol, both at 1,17% (mim)) on the total yield (mass of oleoresin! mass of feed) and the kinetics of ginger oleoresin extraction studied. The experimental setup used has a fixed bed extractor wiyh a diameter2,83xl0.2 m and length of 0,375 m. The assays were done at a CO2 flow rate of 5,23xlO-5kg/s. Typical experimental runs took 7 hours. The duration of the constant extraction rate period ranged from 1,3 to 2,7 hours and the yields varied from 1,93 to 2,65%. The identification of the substances presents in the extracts was done by GC/MS. The extracts analised showed a power antioxidants. They also had a action against some kinds of cancer and some bacterias here studied. Spectrofotometry showed not adequated for gingerol and shogaol quantification. The extracts of the constant rate extration period and the decrescent rate extraction period presented of monoterpens, sesquiterpens, gingerols and shogaols in their composition while the extracts of difusion period showed mainly gingerols and shogaols.
Mestrado
Mestre em Engenharia de Alimentos
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Veggi, Priscilla Carvalho. "Obtenção de extratos vegetais por diferentes metodos de extração : estudo experimental e simulação dos processos". [s.n.], 2009. http://repositorio.unicamp.br/jspui/handle/REPOSIP/254860.
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Orientador: M. Angela de A. MeirelesDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: Neste trabalho é apresentado um estudo comparativo do custo de manufatura para diferentes técnicas de extração: extração com solventes a baixa pressão (LPSE: Low Pressure Solvent Extraction) em taque agitado e percolação, e extração supercrítica (SFE: Supercritical Fluid Extraction). As estimativas dos custos para os processos de extração LPSE por agitação e percolação foram realizadas por meio do simulador de processos SuperPro DesignerÒ. Foi realizado um estudo experimental para a obtenção, por extração supercrítica, de polifenóis de folhas de pitanga (Eugenia uniflora). Para o estudo do aumento de escala, assumiu-se que os parâmetros em escala laboratorial: rendimento da extração, tempo e a relação entre a massa de alimentação e solvente, são mantidos constantes para o equipamento em escala industrial. Assim, as estimativas foram realizadas tendo como base dados de literatura para a matriz vegetal macela (Achyrocline satureioides). Os estudos foram realizados para extratores de 50 L, 100 L e 300 L. Os custos de manufatura para LPSE em taque agitado e percolação foram: US$ 877,21/kg; US$ 698,73/kg; US$ 573,34/kg e US$ 814,46/kg; US$ 567,86/kg; US$ 384,00/kg, respectivamente em extratores de 50 L, 100 L e 300 L. Notou-se a influência dos parâmetros tempo e rendimento no custo dos extratos. Posteriormente, um estudo do custo do extrato através do processo SFE para mesma matriz vegetal foi realizado. Porém, para SFE o custo do extrato foi estimado através do parâmetro tCER, tempo em que aproximadamente 70 % do leito de extração é esgotado, sendo esta uma boa estimativa para o menor tempo de ciclo. O custo de manufatura do extrato obtido por SFE foi US$ 585,49/kg. Uma avaliação comparativa entre os três processos foi realizada e, dentre os principais custos obtidos: de investimento inicial, matéria-prima e utilidades, notou-se que o custo de investimento não é predominante na formação do custo de manufatura. O custo de matéria-prima para alguns dos tamanhos de extratores representou o fator preponderante. Posteriormente à esta etapa, foi realizado o estudo da cinética do processo de extração supercrítica para obtenção do extrato de folhas da pitanga (Eugenia uniflora) a partir de dados otimizados da literatura; este estudo foi realizado em coluna de extração de 300 mL. Utilizou-se temperatura e pressão de 333,15 K e 60 MPa sob diferentes condições de vazão a fim de estudar o comportamento cinético da extração em relação ao rendimento e à presença de compostos voláteis. Ainda foram realizadas análises para identificação dos compostos por cromatografia em camada delgada (CCD) e cromatografia gasosa acoplada à espectrometria de massas (CG-EM). O estudo do aumento de escala foi realizado usando-se uma unidade piloto equipada com dois extratores de 5 L contendo 3 separadores (S1, S2 e S3); como referência foi empregado o ensaio cinético realizado para folhas de pitanga na coluna de 300 mL. Seguindo o critério de aumento de escala em que se mantém constante a proporção entre a massa de solvente e a massa de matéria-prima, o aumento de escala foi de 17 vezes. Para os experimentos foram selecionadas as seguintes condições de operação para os três separadores S1, S2 e S3: 10 MPa/333,15 K; 7 MPa/303,15 K e 3 MPa /313,15 K, respectivamente. Quatro pontos selecionados da cinética de extração em coluna de 300 Ml foram então reproduzidos. O custo do extrato foi estimado utilizando o simulador SuperPro DesignerÒ obtendo-se um custo do manufatura de US$ 449,89/kg
Abstract: In this work a comparative study of the cost of manufacturing (COM) for different extraction techniques is presented: low pressure solvent extraction (LPSE) in agitation and percolation, and supercritical fluid extraction (SFE). The COM estimation was carried using the processes simulator SuperPro Designer®; agitation and percolation LPSE processes were developed in the simulator. An experimental study to obtain poliphenols by supercritical fluid extraction from leaves of pitanga (Eugenia uniflora) was also performed. For the scale-up study it was assumed that the parameters for the laboratorial scale SFE unit: yield of extraction, time and ratio between the feed mass and solvent mass are kept constant for the equipment in industrial scale. The estimations were carried using literature information for the vegetable matrix macela (Achyrocline satureioides). The studies were done for extraction vessels of 50 L, 100 L and 300 L. The COM for LPSE agitation and percolation processes were: US$ 877.21/kg; US$ 698.73/kg; US$ 573.34/kg and US$ 814.46/kg; US$ 567.86/kg; US$ 384.00/kg, respectively for extractors of 50 L, 100 L and 300 L. It was observed the influence of time and yield parameters on the COM. Later, a study of SFE process COM for the same vegetable matrix was done. For SFE the COM was estimated using the tCER parameter as cycle time, where approximately 70% of extraction bed is exhausted, being this a good estimation. The COM of extract obtained by SFE was US$ 585.49/kg. A comparative evaluation between the tree processes was carried out, and among the major costs factors: investment, raw material and utilities, it was observed that the investment cost is not predominant in the COM of the extracts. The raw material cost certain vessel sizes represented the major cost factor. After this step, a study of the SFE kinetics for leaves of pitanga (Eugenia uniflora) was carried out. The operating conditions were selected from optimized data from literature; this study was done in a 300 mL column vessel. It was utilized temperatures and pressure of 333.15 K and 60 MPa under different flow rates in order to study the kinetic behavior of the overall extraction curve and the presence of volatile compounds. Thin layer chromatography (TLC) and gas chromatography-mass spectrometry (GC-MS) analyses were used for identification of the compounds present in the extract. The scale-up study was carried out using a pilot unit equipped with two extractor of 5L vessel containing 3 separators vessels (S1, S2 and S3); as reference the kinetic assay for pitanga leaves in 300 mL column vessel was used. According to the scaleup criterion that the ratio between solvent mass and raw material mass is kept constant, the scale-up was of 17 times. For the experiment the following operation condition for the three separators S1, S2 and S3 were selected: 10 MPa/333.15 K; 7 MPa/303.15 K and 3 MPa /313.15 K, respectively. Four points selected from kinetic experiment in 300 mL column vessel were reproduced. The extract COM was estimated using simulator SuperPro DesignerÒ (US$ 449,89/kg)
Mestrado
Mestre em Engenharia de Alimentos
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Pacetta, Cosmo Fernando. "Estudo de diferentes metodologias para a obtenção de extratos de folhas de oliveira (Olea europaea) contendo oleuropeína". Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/74/74132/tde-05052014-135759/.
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A oleuropeína é o mais abundante biofenol presente nas folhas de oliveira (Olea Europaea), com importantes funções antimicrobiana e antioxidante. Estudos visando à obtenção deste composto têm sido conduzidos, porém, muitos deles utilizam solventes tóxicos e métodos caros. A presente dissertação teve por objetivo estudar diferentes metodologias para a obtenção de extratos de folhas de oliva contendo quantidades significativas de oleuropeína. Os extratos foram obtidos a partir de folhas de oliva micronizadas, com ou sem pré-tratamento para redução do teor de clorofila, submetidas a contatos simples ou múltiplos com diferentes solventes, como dietil éter, clorofórmio, acetona, etanol, 1-propanol, 2-propanol, água e soluções hidroalcoólicas com diferentes concentrações. O contato das folhas micronizadas com os solventes foi promovido pelos seguintes métodos: agitação manual em temperatura ambiente, agitação mecânica a 50 ºC, ultrassom ou uma combinação desses dois últimos, totalizando 38 experimentos, sendo que em 17 destes os extratos foram produzidos na forma líquida e 21 na forma sólida. Os resultados mostraram que, de maneira geral, a etapa prévia de redução do teor da clorofila (realizada através de sucessivos contatos com hexano, diclorometano ou ainda, com CO2 supercrítico) não foi vantajosa, devido à elevada quantidade de solventes utilizados em relação às quantidades de extratos obtidos. Nestes experimentos, a maior concentração de oleuropeína, 1,88%, foi detectada no procedimento em que as folhas micronizadas foram previamente umedecidas com etanol e limpas com CO2 supercrítico, e posteriormente colocadas em contato com a mistura etanol e água, na proporção 1:1, utilizando o ultrassom combinado com a agitação mecânica como método de extração. Nos experimentos finais do trabalho, foi estudada ainda a adição de ácidos orgânicos (cítrico ou acético), juntamente com os solventes hidroalcoólicos (diferentes teores de água) no momento da extração da oleuropeína em banho de ultrassom, utilizando amostras que não foram previamente tratadas para remoção da clorofila. A combinação do ácido acético com a solução etanólica contendo 30 % de água resultou em um extrato com 2,17 % de oleuropeína, em apenas 1 contato com o solvente. Quando três contatos foram utilizados, nestas mesmas condições, o teor de oleuropeína aumentou para 4,8 %, maior do que alguns valores encontrados na literatura, utilizando o mesmo método de extração, indicando que processo ainda pode ser otimizado, utilizando técnicas simples e solventes que não agridam o meio ambiente.Oleuropein is the most abundant biofenol present in olive leaves (Olea europaea), presenting important antioxidant and antimicrobial functions. Studies focusing on obtaining this compound have been conducted; however, many of them use toxic solvents and expensive methods. The present work aimed to study different methodologies for obtaining extracts from olive leaves containing significant amounts of oleuropein. The extracts were obtained from micronized olive leaves, with or without pretreatment for reducing the chlorophyll content, submitted to single and multiple contacts with different solvents such as diethyl ether, chloroform, acetone, ethanol, 1- propanol, 2 -propanol, water and hydroalcoholic solutions at different concentrations. The contact between the micronized leaves and the solvents was promoted by the following methods: manual shaking at room temperature, mechanical agitation at 50 °C, ultrasound or a combination of these last two methods, totaling 38 experiments, from which in 17 of them the extracts were produced in the liquid form, and in 21 in the solid form (as a powder). The results show that, in general, previous step of reducing the content of chlorophyll (performed by successive contacts with hexane, dichloromethane or with supercritical CO2) was not advantageous due to the high amount of solvent used in relation to amounts of extracts. In these experiments, the highest concentration of oleuropein, 1.88 % was detected in the procedure in which the micronized leaves were previously soaked with ethanol and cleaned with supercritical CO2 and then placed in contact with the mixture of ethanol and water in the proportion 1:1, using ultrasound combined with mechanical agitation as extraction method. In the last experiments of the work, the addition of organic acids (citric or acetic acid) together with hydroalcoholic solvents (different water contents) in the extraction of oleuropein in ultrasound was studied, using samples that have not previously been treated for removal of chlorophyll. The combination of acetic acid to the ethanolic solution containing 30 % of water resulted in an extract with 2.17 % of oleuropein, with only one contact to the solvent. When three contacts were used, under the same conditions, the oleuropein content increased to 4.8 %, larger than some values found in the literature, using the same extraction method, indicating that the process can be further optimized using simple techniques and solvents that do not harm the environment.
Książki na temat "Solvents extracts":
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Butz, Martin V., i Esther F. Kutter. Primary Visual Perception from the Bottom Up. Oxford University Press, 2017. http://dx.doi.org/10.1093/acprof:oso/9780198739692.003.0008.
Streszczenie:
This chapter addresses primary visual perception, detailing how visual information comes about and, as a consequence, which visual properties provide particularly useful information about the environment. The brain extracts this information systematically, and also separates redundant and complementary visual information aspects to improve the effectiveness of visual processing. Computationally, image smoothing, edge detectors, and motion detectors must be at work. These need to be applied in a convolutional manner over the fixated area, which are computations that are predestined to be solved by means of cortical columnar structures in the brain. On the next level, the extracted information needs to be integrated to be able to segment and detect object structures. The brain solves this highly challenging problem by incorporating top-down expectations and by integrating complementary visual information aspects, such as light reflections, texture information, line convergence information, shadows, and depth information. In conclusion, the need for integrating top-down visual expectations to form complete and stable perceptions is made explicit.
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Golshekan, Hamid Reza. The kinetics of the extraction of cobalt in a growing drop cell: Organophosphorus acids in growing solvent drops are used to extract cobalt from aqueous phases. A mathematical model describesvariation of extraction rate with concentration, pH and acid type. Bradford, 1986.
Części książek na temat "Solvents extracts":
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Sun, Yingying, Jing Zhang, Shenzhen Xu, Wenhao Li i Changhai Wang. "Growth Inhibition of Karenia mikimitoi by Extracts from Gracilaria lemaneiformis Using Five Solvents". W Advances in Intelligent and Soft Computing, 199–210. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-27537-1_26.
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Manyim, S., A. K. Kiprop, J. I. Mwasiagi i A. C. Mecha. "Dyeing characteristics of different solvent extracts of Euclea divinorum on cotton fabric". W Advances in Phytochemistry, Textile and Renewable Energy Research for Industrial Growth, 136–42. London: CRC Press, 2022. http://dx.doi.org/10.1201/9781003221968-18.
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Bryant, Randal E., Armin Biere i Marijn J. H. Heule. "Clausal Proofs for Pseudo-Boolean Reasoning". W Tools and Algorithms for the Construction and Analysis of Systems, 443–61. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-99524-9_25.
Streszczenie:
AbstractWhen augmented with a Pseudo-Boolean (PB) solver, a Boolean satisfiability (SAT) solver can apply apply powerful reasoning methods to determine when a set of parity or cardinality constraints, extracted from the clauses of the input formula, has no solution. By converting the intermediate constraints generated by the PB solver into ordered binary decision diagrams (BDDs), a proof-generating, BDD-based SAT solver can then produce a clausal proof that the input formula is unsatisfiable. Working together, the two solvers can generate proofs of unsatisfiability for problems that are intractable for other proof-generating SAT solvers. The PB solver can, at times, detect that the proof can exploit modular arithmetic to give smaller BDD representations and therefore shorter proofs.
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Doe, P., C. A. Danquah, K. A. Ohemeng, S. Nutakor, B. Z. Braimah, A. Amaglo, M. Abdul-Fatah i in. "Acute and Sub-acute Toxicity Studies of Solvent Extracts of Crinum pedunculatum Bulbs R.Br". W Sustainable Education and Development – Sustainable Industrialization and Innovation, 752–62. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-25998-2_59.
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Macaev, Fliur Z. "Green Chemistry Protocols: Specific Ionic Liquids as Recyclable Reagents, Catalysts, Solvents and Extractors". W Environmental Security Assessment and Management of Obsolete Pesticides in Southeast Europe, 271–86. Dordrecht: Springer Netherlands, 2013. http://dx.doi.org/10.1007/978-94-007-6461-3_25.
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Yusof, Rizana, Siti Zawani Ahmad Zaini i Mohd Azhar Azman. "Characterization of Pectin Extracted from Guava Peels Using Deep Eutectic Solvent and Citric Acid". W Charting the Sustainable Future of ASEAN in Science and Technology, 421–33. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-3434-8_36.
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Osmić, Selma, Sabina Begić i Vladan Mićić. "The Effect of Concentration of Methanol as a Solvent on the Antioxidative Activity of Sage Extract". W Lecture Notes in Networks and Systems, 480–90. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-90893-9_56.
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Zlatkin, Ilia, i Grigory Fedyukovich. "Maximizing Branch Coverage with Constrained Horn Clauses". W Tools and Algorithms for the Construction and Analysis of Systems, 254–72. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-99527-0_14.
Streszczenie:
AbstractState-of-the-art solvers for constrained Horn clauses (CHC) are successfully used to generate reachability facts from symbolic encodings of programs. In this paper, we present a new application to test-case generation: if a block of code is provably unreachable, no test case can be generated allowing to explore other blocks of code. Our new approach uses CHC to incrementally construct different program unrollings and extract test cases from models of satisfiable formulas. At the same time, a CHC solver keeps track of CHCs that represent unreachable blocks of code which makes the unrolling process more efficient. In practice, this lets our approach to terminate early while guaranteeing maximal coverage. Our implementation called Horntinuum exhibits promising performance: it generates high coverage in the majority of cases and spends less time on average than state-of-the-art.
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Dixit, Shikha, i Sugandha Tiwari. "Comparative Analysis of Bioactive Compounds for Euphorbia Hirta L. Leaves Extract in Aqueous, Ethanol, and Methanol Solvents Using GC-MS". W Proceedings of the International Conference on Intelligent Vision and Computing (ICIVC 2021), 530–40. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-97196-0_44.
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Kalidoss, R., M. Mariraj, M. Shenbagam, J. Merlin Seles, K. Arun Prasath, N. Rajaprabu i P. Ponmurugan. "Anti-microbial and Anti-oxidant Properties of Solvent Extract of Lichen Species Collected from Kodaikanal Hills, Western Ghats of Tamil Nadu". W Phytomedicine, 53–61. First edition. | Boca Raton, FL : CRC Press, 2020.: CRC Press, 2020. http://dx.doi.org/10.1201/9781003014898-8.
Streszczenia konferencji na temat "Solvents extracts":
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Som, Ayub Md, Norizan Ahmat, Hairul Amani Abdul Hamid, Siti Raihanah Abdul Rahman, Nurul Amirrah Rahimudin, Nur Amira Zainidi i Adilah Amirah Ayub. "Phytochemical Screening and Antioxidant Activity of <i>Hylocereus undatus</i> Foliage: Effects of Using Different Drying and Assays Methods". W 5th International Conference on Global Sustainability and Chemical Engineering 2021 (ICGSCE2021). Switzerland: Trans Tech Publications Ltd, 2023. http://dx.doi.org/10.4028/p-m2r02u.
Streszczenie:
Phytochemical screening was conducted on Hylocereusundatus foliage to determine the presence of alkaloids, flavonoids, tannins, and saponins using methanol and chloroform solvents via oven-dried and open air-dried methods. As for the antioxidant activity, powdered Hylocereusundatus foliage were extracted using both solvents through Ferric Reduction Antioxidant Power (FRAP) assay; and the findings were then compared to 2,2-Diphenyl-1-Ipicrylhydrazyl (DPPH) assay from previous studies. Results revealed that for both methods in phytochemical screening, flavonoids were present only in methanol extract; however, saponins were present in both extracts. No alkaloid and tannins were present in both extracts using both methods. Antioxidant activity results revealed that the methanol extract (59.05%) and chloroform extract (20.58%) using the FRAP assay were comparable to that of DPPH assay in which methanol extract (88.81%) and chloroform extract (38.30%) were obtained. It concludes that Hylocereusundatus has comparable phytochemical constituents and antioxidant activity based on the different drying and assay methods.
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Lv, Guoying, Zuofa Zhang, Huijuan Pan i Leifa Fan. "Antioxidant Properties of Different Solvents Extracts from Three Edible Mushrooms". W 2009 3rd International Conference on Bioinformatics and Biomedical Engineering (iCBBE). IEEE, 2009. http://dx.doi.org/10.1109/icbbe.2009.5162375.
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"Determination of Antioxidant Property, Total Phenolics Content, and α-Glucosidase Inhibitory Activity of Different Solvent Extracts of Defatted and Non-Defatted Peanut Skins". W 4th International Conference on Biological & Health Sciences (CIC-BIOHS’2022). Cihan University, 2022. http://dx.doi.org/10.24086/biohs2022/paper.781.
Streszczenie:
Peanut skins are by-product with little economic value. The effect of different solvents, on the total phenolic content (TPC), antioxidant property and in vitro antidiabetic activity of defatted and non-defatted peanut skins was determined. TPC was estimated using Folin-Ciocalteau reagent. Antioxidant property was evaluated using ferric reducing antioxidant power (FRAP) and 2, 2-diphenyl-1- picrylhydrazyl (DPPH) radical scavenging capacity methods, α-glucosidase inhibition was evaluated using 4- nitrophenyl α-D-glucopyranoside (pNPG) method. Peanut skin of the defatted extracted with ethanol had the much of the content of total phenolics (391.76 mg/g GAE). Highest DPPH scavenging property was found in the methanolic extract of defatted peanut skins with IC50 value of 15.00 ± 1.00 μg/mL, while highest FRAP value was found in the aqueous extract of non-defatted extracts. Aqueous extracts demonstrated stronger inhibitory property against α-glucosidase and had IC50 of 16.33 ± 1.15 and 16.33 ± 8.50 μg/mL for defatted and non-defatted extracts, respectively. The finding of the present shows that peanut skins are important by-product for utilization as natural antioxidant and α-glucosidase inhibitors.
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Viñas-Ospino, Adriana, Manuela Panić, Ivana Radojčić-Redovniković, Jesús Blesa, Ana Frígola, María José Esteve i Daniel López-Malo. "Hydrophobic and Hydrophilic Deep Eutectic Solvents to Extract Carotenoids from Orange Peels and Obtain Green Extracts". W Foods 2022. Basel Switzerland: MDPI, 2022. http://dx.doi.org/10.3390/foods2022-12978.
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Konrade, Daiga, i Kriss Spalvins. "Extraction of bioactives from pumpkin by-products and determination of their antioxidant activity". W Research for Rural Development 2022 : annual 28th international scientific conference proceedings. Latvia University of Life Sciences and Technologies, 2022. http://dx.doi.org/10.22616/rrd.28.2022.016.
Streszczenie:
Agro-industrial and food processing from pumpkins (Cucurbitaceae) produces a large number of by-products: bark, pomace, seeds still rich in bioactive compounds, especially carotenoids and green pigments (proto chlorophyll (a and b) and proto pheophytin (a and b)), which exhibit a broad spectrum of health-promoting effects and can be used as ingredients in functional food and cosmetics. For extraction of bioactive compounds from dried pumpkin by-products different methods were used: supercritical CO2, Soxhlet extraction with n- hexane, ethanol. Vegetable oils (rapeseed, coconut, grapeseed and olive oil) were used as green solvent alternatives to conventional organic solvents for carotenoid extraction. Detection and analyses of chlorophylls and carotenoids was done with hexane/acetone, cyclohexane, ethanol as solvents. The aim of this study was to use pumpkin by-products for extraction of high-value bioactive compounds with different methods, to determine antioxidant´s content and profile – carotenoids (ß-carotene, lutein, lycopene, zeaxanthin), pigments (chlorophylls a, chlorophylls b) with different solvents and to find out what solvent can be used for detection of pigments and carotenoids; to determine antiradical scavenging activity of biologically active compounds in extracts from pumpkin by-products (peel and hulled seeds).
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Saldana, Marleny D. "Effect of pressurized fluids on the extraction of phenolics/anthocyanins from crops and by-products". W 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/pnme7357.
Streszczenie:
Phenolics found in various crops and by-products have antioxidant and antimicrobial activities and their consumption have been associated with health benefits. For example, a by-product of the cranberry juice industry is cranberry pomace, which is considered a rich source of anthocyanins. Research in my laboratory has focused on the use of pressurized fluids to extract these phenolic compounds to be used in various applications. Pressurized fluids, such as subcritical water, pressurized ethanol and supercritical CO2 (SC-CO2) as “green†and environmentally friendly solvents, can be used for the extraction of phenolic compounds from crops and by-products as well as for enzymatic reactions involving phenolic acids. Phenolic compounds were extracted from various crops and by-products using pressurized fluids in stainless steel reactors at different temperatures, pressures and times. Extracts obtained after crop and by-product treatment using pressurized fluids were evaluated for their phenolic content and antioxidant activity. Anthocyanins were obtained from cranberry pomace using pressurized fluids. Results also indicated that the total phenolic content and antioxidant activity of the extracts from other crops and by-products increased with extraction temperature. In addition, a phenolic acid was reacted with triglycerides of flax oil using lipase enzyme in SC-CO2 media in a laboratory-scale supercritical system at different temperatures ranging from 40 to 80˚C, pressures from 40 to 350 bar and times of up to 53 h. Results have shown that SC-CO2 is a promising green solvent for the enzymatic synthesis of phenolic lipids. Results also have shown that phenolic acids can be processed using pressurized fluids for different applications.
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Castejon, Natalia. "Eco-friendly Strategies to Produce Bioactive Lipids from the omega-3 Rich Microalga Nannochloropsis Gaditana". W 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/rwfn7404.
Streszczenie:
Microalgae are considered a promising alternative source of omega-3 long chain-polyunsaturated fatty acids (ω-3 LC-PUFAs) since they are the primary producers of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids in the marine environment. Extraction methods commonly used for the isolation of these bioactives are based on conventional techniques, which imply the use of high volumes of organic solvents and high energy requirements, producing health and environmental problems. In this sense, greener alternatives need to be developed to meet the global consumer demand for natural ingredients and eco-friendly products. In this work, the use of ultrasonic-assisted enzymatic extraction (UAEE) technology in combination with environmentally friendly solvents was evaluated as a green strategy to efficiently extract the omega-3 lipids from the microalga Nannochloropsis gaditana. The microalgal biomass was pretreated with different commercial enzymes (Viscozyme® L, Celluclast® 1.5 L, and Saczyme® Yield) and the results were compared with the traditional Folch method (2:1 chloroform/methanol). A promising extraction approach was developed using Saczyme® Yield and ethanol as solvent, achieving a lipid yield of 25.7% ± 0.5, comparable to the results obtained with the traditional method (27.3% ± 0.7) (p > 0.05). Similar omega-3 content was found by GC-MS analysis for both lipid extracts (30.2% ± 2.9 and 29.2% ± 1.0 for the green and the traditional method, respectively), showing that the environmentally friendly approaches did not negatively affect the fatty acid profile. Additionally, the bioactivity of the produced lipids was investigated by a spectrum of in vitro cell-based assays measuring potential endpoints of interest like cytotoxicity, antioxidant and anti-inflammatory activities. In conclusion, this work provides relevant results for new eco-friendly extraction approaches to produce functional omega-3 lipids with potential applications in the food industry, avoiding the use of toxic solvents and reducing the environmental impact.
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Hameed, Anmar, Gires Usup i Asmat Ahmad. "Effect of different solvents extracts and mode of action of Loktanella spp. Gb03 on toxic dinoflagellate". W THE 2016 UKM FST POSTGRADUATE COLLOQUIUM: Proceedings of the Universiti Kebangsaan Malaysia, Faculty of Science and Technology 2016 Postgraduate Colloquium. Author(s), 2016. http://dx.doi.org/10.1063/1.4966711.
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Buang, Yohanes, Suwari i Antonius R. B. Ola. "Effects of pH changes in water-based solvents to isolate antibacterial activated extracts of natural products". W INTERNATIONAL CONFERENCE AND WORKSHOP ON MATHEMATICAL ANALYSIS AND ITS APPLICATIONS (ICWOMAA 2017). Author(s), 2017. http://dx.doi.org/10.1063/1.5015997.
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Felicia, Suciu, Roșca Adrian Cosmin, Lupu Carmen, Popescu Antoanela i Badea Victoria. "DETERMINATION OF POLYPHENOLIC COMPOUNDS OF LYSIMACHIA NUMMULARIA L." W GEOLINKS Conference Proceedings. Saima Consult Ltd, 2021. http://dx.doi.org/10.32008/geolinks2021/b1/v3/08.
Streszczenie:
"The history of medicinal plants is associated with the evolution of civilization. In all regions of the world, the history of nations shows that these plants have always occupied an important place in medicine, in cosmetic products, and culinary preparations. The paper aims to determine the total polyphenols in different parts of the species Lysimachia nummularia L. In our study, we focused on the extraction of polyphenolic compounds in different solvents. The solvents used in the extraction were: 40% ethanol, concentrated methanol, in water. The total polyphenol content was determined by spectrophotometric methods, a method from the European Pharmacopoeia 10.0, with minor modifications. The total polyphenol content of different extracts varied depending on the extraction process. Different parts of the plant and different solvents were used in the determinations carried out to establish the optimal extraction method for the organs of Lysimachia nummularia L."
Raporty organizacyjne na temat "Solvents extracts":
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McHenry, E. R. Evaluation of pitches and cokes from solvent-extracted coal materials. Office of Scientific and Technical Information (OSTI), grudzień 1996. http://dx.doi.org/10.2172/451287.
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Ra, Jong-Hwan, Masaya Nakamura i Ju-Sung Kim. Effect of Solvent Concentration on Phenolic Content and Biological Activity of Sasa Quelpaertensis Nakai Ethanol Leaf Extract. "Prof. Marin Drinov" Publishing House of Bulgarian Academy of Sciences, luty 2018. http://dx.doi.org/10.7546/crabs.2018.02.07.
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Ra, Jong-Hwan, Masaya Nakamura i Ju-Sung Kim. Effect of Solvent Concentration on Phenolic Content and Biological Activity of Sasa Quelpaertensis Nakai Ethanol Leaf Extract. "Prof. Marin Drinov" Publishing House of Bulgarian Academy of Sciences, luty 2018. http://dx.doi.org/10.7546/grabs2018.2.07.
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Poole, Loree Joanne, i C. Judson King. Novel Regenerated Solvent Extraction Processes for the Recovery of Carboxylic Acids or Ammonia from Aqueous Solutions Part I. Regeneration of Amine-Carboxylic Acid Extracts. Office of Scientific and Technical Information (OSTI), marzec 1990. http://dx.doi.org/10.2172/937438.
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Science, Fera. Analysis of CBD Products. Food Standards Agency, listopad 2022. http://dx.doi.org/10.46756/sci.fsa.cis490.
Streszczenie:
The Food Standards Agency commissioned Fera Science Ltd. to carry out a survey to obtain a snapshot of CBD products on sale in England and Wales in order to inform FSA risk assessment of CBD products. Thirty CBD products were purchased from a range of online sellers from England and Wales. Samples comprised of two broad categories: oils and sprays, and edibles (including beverages). The sampling followed a scheme suggested by FSA. This is not a statistically representative sample of the market and instead provides a snapshot of the current market, to assist the design of future sampling and surveillance activity. There is the potential for residues of chemicals to be present in CBD products as a result of their natural occurrence in the raw material or arising from the manufacturing process, for example, mycotoxins, metals, pesticides, and the residues of solvents used to extract CBD. This study informs the FSA’s understanding of the type and levels of contaminants that may arise in CBD products. A wide range of analysis on CBD products was undertaken using accredited methods, for heavy metals, Polycyclic Aromatic Hydrocarbons (PAHs), pesticides, mycotoxins, CBD content and cannabinoid profiles. Analysis for residual solvents and additional mycotoxins was also carried out, but these were not accredited. The results of testing found the following: Heavy metals (cadmium, mercury & lead) and arsenic were not detected in the majority of samples, meaning levels were below the limits of quantification of the method. Seven samples contained lead, four samples arsenic and two samples contained cadmium. Mercury was not found in any sample. A definitive statement as to whether products exceed maximum levels cannot be made due to uncertainty as to whether products would be classified as a food (i.e. oil) or a food supplement. A low incidence of low levels of mycotoxins, with Fusarium mycotoxins found more frequently than aflatoxins and ochratoxin A, mostly at the methods reporting limit. Three samples were found to contain ochratoxin A at the methods reporting limit. A total of seven pesticide residues were found across all of the products (each product was tested for over 400 pesticides). There are no specific Maximum Residue Limits (MRL) for CBD products. One oil product was found to have PAHs above the regulated levels, if classed as a product for direct consumption. If classed as a food supplement the PAHs were within regulated levels. Three samples contained residual solvents. One product was over the MRL. Most products contained CBD close to the declared value. Two oils had substantially different levels than that declared (one higher and one lower). CBD was not detected in one of the drink products. These are potentially non-compliant with compositional and standards requirements. Delta 9-THC was detected in 87 % (26) of the samples analysed. Of these 40% (12) were found to have THC+ (the total sum of illicit cannabinoids in the product) above the 1mg threshold outlined in current Home Office guidance (Opens in a new window).
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Crouch, Rebecca, Jared Smith, Bobbi Stromer, Christian Hubley, Samuel Beal, Guilherme Lotufo, Afrachanna Butler i in. Preparative, extraction, and analytical methods for simultaneous determination of legacy and insensitive munition (IM) constituents in aqueous, soil or sediment, and tissue matrices. Engineer Research and Development Center (U.S.), sierpień 2021. http://dx.doi.org/10.21079/11681/41480.
Streszczenie:
No standard method exists for determining levels of insensitive munition (IM) compounds in environmental matrices. This project resulted in new methods of extraction, analytical separation and quantitation of 17 legacy and 7 IM compounds, daughter products of IM, and other munition compounds absent from USEPA Method 8330B. Extraction methods were developed for aqueous (direct-injection and solid-phase extraction [SPE]), soil, sediment, and tissue samples using laboratory-spiked samples. Aqueous methods were tested on 5 water sources, with 23 of 24 compounds recovered within DoD QSM Ver5.2 limits. New solvent extraction (SE) methods enabled recovery of all 24 compounds from 6 soils within QSM limits, and a majority of the 24 compounds were recovered at acceptable levels from 4 tissues types. A modified chromatographic treatment method removed analytical interferences from tissue extracts. Two orthogonal high-performance liquid chromatography-ultraviolet (HPLC-UV) separation methods, along with an HPLC–mass spectrometric (HPLC-MS) method, were developed. Implementing these new methods should reduce labor and supply costs by approximately 50%, requiring a single extraction and sample preparation, and 2 analyses rather than 4. These new methods will support environmental monitoring of IM and facilitate execution of risk-related studies to determine long-term effects of IM compounds.
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Crouch, Rebecca, Jared Smith, Bobbi Stromer, Christian Hubley, Samuel Beal, Guilherme Lotufo, Afrachanna Butler i in. Methods for simultaneous determination of legacy and insensitive munition (IM) constituents in aqueous, soil/sediment, and tissue matrices. Engineer Research and Development Center (U.S.), sierpień 2021. http://dx.doi.org/10.21079/11681/41720.
Streszczenie:
Currently, no standard method exists for analyzing insensitive munition (IM) compounds in environmental matrices, with or without concurrent legacy munition compounds, resulting in potentially inaccurate determinations. The primary objective of this work was to develop new methods of extraction, pre-concentration, and analytical separation/quantitation of 17 legacy munition compounds along with several additional IM compounds, IM breakdown products, and other munition compounds that are not currently included in U.S. Environmental Protection Agency (EPA) Method 8330B. Analytical methods were developed to enable sensitive, simultaneous detection and quantitation of the 24 IM and legacy compounds, including two orthogonal high-performance liquid chromatography (HPLC) column separations with either ultraviolet (UV) or mass spectrometric (MS) detection. Procedures were developed for simultaneous extraction of all 24 analytes and two surrogates (1,2-dinitrobenzene, 1,2-DNB; o-NBA) from high- and low-level aqueous matrices and solid matrices, using acidification, solid phase extraction (SPE), or solvent extraction (SE), respectively. The majority of compounds were recovered from four tissue types within current limits for solids, with generally low recovery only for Tetryl (from 4 to 62%). A preparatory chromatographic interference removal procedure was adapted for tissue extracts, as various analytical interferences were observed for all studied tissue types.
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Glasscott, Matthew, Johanna Jernberg, Erik Alberts i Lee Moores. Toward the electrochemical detection of 2,4-dinitroanisole (DNAN) and pentaerythritol tetranitrate (PETN). Engineer Research and Development Center (U.S.), marzec 2022. http://dx.doi.org/10.21079/11681/43826.
Streszczenie:
Analytical methods to rapidly detect explosive compounds with high precision are paramount for applications ranging from national security to environmental remediation. This report demonstrates two proof-of-concept electroanalytical methods for the quantification of 2,4-dinitroanisol (DNAN) and pentaerythritol tetranitrate (PETN). For the first time, DNAN reduction was analyzed and compared at a bare graphitic carbon electrode, a polyaniline-modified (PANI) electrode, and a molecularly imprinted polymer (MIP) electrode utilizing PANI to explore the effect of surface-area and preconcentration affinity on the analytical response. Since some explosive compounds such as PETN are not appreciably soluble in water (<10 μg/L), necessitating a different solvent system to permit direct detection via electrochemical reduction. A 1,2-dichloroethane system was explored as a possibility by generating a liquid-liquid extraction-based sensor exploiting the immiscibility of 1,2-dichloroethane and water. The reduction process was explored using a scan rate analysis to extract a diffusion coefficient of 6.67 x 10⁻⁶ cm/s, in agreement with literature values for similarly structured nitrate esters. Once further refined, these techniques may be extended to other explosives and combined with portable electrochemical hardware to bring real-time chemical information to soldiers and citizens alike.
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Badia, S., A. Martín, J. Principe, C. Soriano i R. Rossi. D3.1 Report on nonlinear domain decomposition preconditioners and release of the solvers. Scipedia, 2021. http://dx.doi.org/10.23967/exaqute.2021.2.021.
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This document describes the industrial application, on which the developments of the project are implemented, and the CFD set-up. The developments are implemented over six analysis cases with increasing complexity starting from a 2D geometry with mean wind inflow to a 3D geometry with turbulent inflow and real-time shape optimization. The application represents the CAARC tall building model, which has served as a benchmark model for many studies since the 1970’s when it was first developed. Base moments (bending and torsional moments) of the building are extracted for validation by comparison of the results with the benchmark study. Page 3 of 19 Deliverable 7.1
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Hefetz, Abraham, i Justin O. Schmidt. Use of Bee-Borne Attractants for Pollination of Nonrewarding Flowers: Model System of Male-Sterile Tomato Flowers. United States Department of Agriculture, październik 2003. http://dx.doi.org/10.32747/2003.7586462.bard.
Streszczenie:
The use of bee natural product for enhancing pollination is especially valuable in problematic crops that are generally avoided by bees. In the present research we attempted to enhance bee visitation to Male Sterile (M-S) tomato flowers generally used in the production of hybrid seeds. These flowers that lack both pollen and nectar are unattractive to bees that learn rapidly to avoid them. The specific objects were to elucidate the chemical composition of the exocrine products of two bumble bee species the North American Bombus impatiens and the Israeli B. terrestris. Of these, to isolate and identify a bee attractant which when sprayed on M-S tomato flowers will enhance bee visitation, and to provide a procedure of the pheromone application regime. During the research we realized that our knowledge of B. impatiens is too little and we narrowed the objective to learning the basic social behavior of the bees and the pattern of foraging in a flight chamber and how it is affected by biogenic amines. Colonies of B. impatiens are characterized by a high number of workers and a relatively small number of queens. Size differences between queens and workers are pronounced and the queen seems to have full control over egg laying. Only about 9% of the workers in mature colonies had mature oocytes, and there were no signs of a "competition phase" as we know in B. terrestris. Queens and workers differ in their exocrine bouquet. Queen's Dufour's gland possesses a series of linear, saturated and unsaturated hydrocarbons whereas that of workers contains in addition a series of wax-type esters. Bees were trained to either visit or avoid artificially scented electronic flowers in a flight chamber. Since bee also learned to avoid scented non-rewarding flowers we attempted to interfere with this learning. We tested the effect of octopamine, a biogenic amine affecting bee behavior, on the choice behavior of free-flying bumblebees. Our results show that octopamine had no significant effect on the bees' equilibrium choice or on the overall rate of the behavioral change in response to the change in reward. Rather, octopamine significantly affected the time interval between the change in reward status and the initiation of behavioral change in the bee. In B. terrestris we studied the foraging pattern of the bees on tomato flowers in a semi commercial greenhouse in Yad Mordechai. Bee learned very quickly to avoid the non- rewarding M-S flowers, irrespective of their arrangement in the plot, i.e., their mixing with normal, pollen bearing flowers. However, bees seem to "forget" this information during the night since the foraging pattern repeats itself the next morning. Several exocrine products were tested as visitation enhancers. Among these, tarsal gland extracts are the most attractive. The compounds identified in the tarsal gland extract are mostly linear saturated hydrocarbons with small amounts of unsaturated ones. Application was performed every second day on leaves in selected inflorescences. Bee visitation increased significantly in the treated inflorescences as compared to the control, solvent treated. Treatment of the anthers cone was more effective than on the flower petals or the surrounding leaves. Methanol proved to be a non-flower-destructive solvent. We have shown that bumble bees (B. terrestris) can be manipulated by bee-borne attractants to visit non-rewarding flowers. We have further demonstrated that the bees learning ability can be manipulated by applying exogenously octopamine. Both methods can be additively applied in enhancing pollination of desired crops. Such manipulation will be especially useful in tomato cultivation for hybrid seed production.