• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 8
  • 3
  • 3
  • 2
  • Tagged with
  • 16
  • 16
  • 16
  • 8
  • 6
  • 5
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 3
  • 3
  • 3
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Ultrasound Assisted Extraction Of Lipids And Antioxidants From Wheat Germ

Melikoglu, Mehmet 01 February 2005 (has links) (PDF)
The aim of this thesis work was to extract lipids and antioxidants from wheat germ using an ultrasonic bath. Alternative solvents: Ethanol, isopropanol and acetone were used for the extraction purposes and for the fat content determination hexane was used. Alternative solvents dissolve wax, phospholipids and some other proteins because of their polar nature which increased the yield. Since waxes and some proteins can be added to the soaps and creams which were made from carrier oils, obtaining these substances together with the oil in the extract was very useful. For isopropanol a linear relation was found between the extract ratio and ultrasonication time. The highest extract ratios were achieved with ethanol. For 30 minutes of ultrasonication 0.10 g extract / g germ was obtained. After the extraction in order to enhance the phase separation between the solid phase (germ and other solids) and the extract phase, combinations of centrifugation, storage in the refrigerator and decantation were tested. The technique involving storage the extracts in the refrigerator for 24 hours and centrifugation at 2800 rpm for 20 minutes gave the second highest yield but the best phase separation. Ethanol extracts from both roasted and nonroasted wheat germs were characterized in terms of their total polyphenol contents. For non roasted wheat germs total polyphenol contents of 200 mg gallic acid / L solution and for roasted wheat germs an average of 170 mg gallic acid / L solution were obtained for 30 minutes of ultrasonic extraction. For nonroasted wheat germs weak but significant linear relations were found between total polyphenol contents of the extracts and ultrasonication time.
2

Ultrasound Assisted And Supercritical Carbon Dioxide Extraction Of Antioxidants From Roasted Wheat Germ

Gelmez, Nilufer 01 February 2008 (has links) (PDF)
This study covers the extraction of antioxidants from wheat germ / which is the byproduct of the flour-milling industry and a rich source of antioxidants / with Ultrasound Assisted (UAE) and Supercritical Carbon Dioxide (SC-CO2) extractions. Extraction conditions were ultrasonication time (1&ndash / 11 min), temperature (20&ndash / 60&deg / C) and ethanol level (5&ndash / 95%) for UAE, and pressure (148&ndash / 602 bar), temperature (40&ndash / 60&deg / C) and time (10&ndash / 60 min) for SC-CO2 extraction. The extraction conditions were optimized based on yield (%), total phenolic contents (TPC, mg GAE/g extract) and antioxidant activities (AA, mg scavenged DPPH&amp / #729 / /g extract) of the extracts, using Central Composite Rotatable Design. Total tocopherol contents (TTC) of the extracts were determined, as well. UAE (at 60&deg / C) with low ethanol level (~5-30%) and short times (1-3 min) provided protein rich extracts with high yield, medium TPC and AA. On the other hand, with high ethanol level (~90%) and long times (6-11 min), waxy structured extracts with low yield but high TPC and AA were obtained. SC-CO2 extraction at 442 bar, 40&ordm / C and 48 min. enabled almost 100% recovery of wheat germ oil (9% yield) but TPC and AA of the extracts were low. On the contrary, the extracts obtained at lower pressures (~150bar) and shorter times (~10 min) at 50-60&ordm / C had high TPC and AA since the oil yield was low. However, TPC and AA of these extracts were only half of those extracted by UAE. Maximum tocopherol (7.142 mg tocopherol/g extract) extraction was achieved at 240 bar, 56&ordm / C for 20 min. Both of the methods extracted high amounts of tocopherols from roasted wheat germ (SC-CO2 extraction / 0.31 mg tocopherol/g germ, UAE / 0.33 mg tocopherol/g germ) but TTC of the extracts obtained by SC-CO2 extraction was superior compared to 1.170 mg tocopherol/g extract obtained by UAE at 9 min, 58&ordm / C and 95% ethanol level. All these extracts with different characteristics have potential uses in cosmetic and food industry depending on the targeted specific application.
3

Recuperação de compostos bioativos do resíduo do processamento do café (silverskin) : otimização do processo de extração; caracterização química, capacidade antioxidante e toxicidade dos extratos

Santos, Anai Loreiro dos January 2018 (has links)
O silverskin é um resíduo, rico em compostos antioxidantes, como o ácido 5-cafeoilquínico (5-CQA) e a cafeína (CAF), produzido durante a torrefação dos grãos de café. O objetivo deste estudo foi desenvolver uma metodologia de extração, aliando a extração assistida por ultrassom e o planejamento de experimentos, para a recuperação simultânea do 5-CQA e da CAF da silverskin. Os extratos gerados foram caracterizados e tiveram a capacidade antioxidante e a toxicidade investigadas. A metodologia de superfície de resposta e a função Desejabilidade foram empregadas na otimização da extração. A LC-DAD/MSn foi utilizada para a caracterização dos extratos, os métodos de sequestro do radical DPPH e de redução do ferro (FRAP), para avaliar a capacidade antioxidante; enquanto o ensaio da Artemia salina foi usando para avaliar a toxicidade. As condições ótimas de extração foram: 45 % de etanol em água como solvente de extração, razão amostra-solvente 1/20, extração por 7 min a 59 °C, com rendimentos de 5-ACQ e CAF de respectivamente 2,00 e 6,26 mg g-1. No total, 9 derivados clorogênicos foram tentativamente identificados. Os teores de teofilina, ácido cafeico e derivados clorogênicos foram respectivamente: 0,53, 0,06 e 4,40 mg g-1. O extrato demonstrou considerável capacidade antioxidante, com concentração eficiente de 46,87 mg L-1 e capacidade redutora de ferro de 152,71 μM de FeSO4 g-1, além de alta toxicidade. O método desenvolvido obteve rendimento similar ao da extração sólido-líquido para o 5-ACQ. / Silverskin is a waste generated during the coffee beans roasting. This residue has been showing antioxidant compounds, mainly 5-caffeoylquinic acid (5-CQA) and caffeine (CAF). The aim of this study was used the design of experiments and ultrasound-assisted extraction to develop an extraction method for the efficient recovery of 5-CQA and CAF from silverskin, simultaneously. In addition, the optimized extract was characterized, and its antioxidant capacity and acute toxicity were investigated. The response surface methodology and Desirability function were employed to optimize the extraction. The chemical characterization was carry out by LC-DAD/ESI-MSn. Antioxidant capacity was evaluated by DPPH (2, 2-diphenyl-1 picryl hydrazyl) and FRAP (ferric reducing antioxidant power) methods and the acute toxicity by Artemia salina assay. The optimal extraction conditions were 45.0 % ethanol in water, the solid-to-liquid ratio was 1:20, and extraction for 7.0 min at 59 °C. Under optimal conditions, the yield of 5-CQA and CAF were 2.00 and 6.26 mg g-1, respectively. Theophylline, caffeic acid, and total chlorogenic acid concentrations were 0.53, 0.06 e 4.40 mg g-1, respectively and 9 chlorogenic acids were identified in the extract. The extract showed considerable antioxidant capacity, with efficient concentration value of 46,87 mg L-1 in the DPPH assay and 152,71 μM FeSO4 g-1 (FRAP) and high toxicity. The developed extraction methodology showed similar performance as solid-liquid extraction to 5-CQA yield.
4

Recuperação de compostos bioativos do resíduo do processamento do café (silverskin) : otimização do processo de extração; caracterização química, capacidade antioxidante e toxicidade dos extratos

Santos, Anai Loreiro dos January 2018 (has links)
O silverskin é um resíduo, rico em compostos antioxidantes, como o ácido 5-cafeoilquínico (5-CQA) e a cafeína (CAF), produzido durante a torrefação dos grãos de café. O objetivo deste estudo foi desenvolver uma metodologia de extração, aliando a extração assistida por ultrassom e o planejamento de experimentos, para a recuperação simultânea do 5-CQA e da CAF da silverskin. Os extratos gerados foram caracterizados e tiveram a capacidade antioxidante e a toxicidade investigadas. A metodologia de superfície de resposta e a função Desejabilidade foram empregadas na otimização da extração. A LC-DAD/MSn foi utilizada para a caracterização dos extratos, os métodos de sequestro do radical DPPH e de redução do ferro (FRAP), para avaliar a capacidade antioxidante; enquanto o ensaio da Artemia salina foi usando para avaliar a toxicidade. As condições ótimas de extração foram: 45 % de etanol em água como solvente de extração, razão amostra-solvente 1/20, extração por 7 min a 59 °C, com rendimentos de 5-ACQ e CAF de respectivamente 2,00 e 6,26 mg g-1. No total, 9 derivados clorogênicos foram tentativamente identificados. Os teores de teofilina, ácido cafeico e derivados clorogênicos foram respectivamente: 0,53, 0,06 e 4,40 mg g-1. O extrato demonstrou considerável capacidade antioxidante, com concentração eficiente de 46,87 mg L-1 e capacidade redutora de ferro de 152,71 μM de FeSO4 g-1, além de alta toxicidade. O método desenvolvido obteve rendimento similar ao da extração sólido-líquido para o 5-ACQ. / Silverskin is a waste generated during the coffee beans roasting. This residue has been showing antioxidant compounds, mainly 5-caffeoylquinic acid (5-CQA) and caffeine (CAF). The aim of this study was used the design of experiments and ultrasound-assisted extraction to develop an extraction method for the efficient recovery of 5-CQA and CAF from silverskin, simultaneously. In addition, the optimized extract was characterized, and its antioxidant capacity and acute toxicity were investigated. The response surface methodology and Desirability function were employed to optimize the extraction. The chemical characterization was carry out by LC-DAD/ESI-MSn. Antioxidant capacity was evaluated by DPPH (2, 2-diphenyl-1 picryl hydrazyl) and FRAP (ferric reducing antioxidant power) methods and the acute toxicity by Artemia salina assay. The optimal extraction conditions were 45.0 % ethanol in water, the solid-to-liquid ratio was 1:20, and extraction for 7.0 min at 59 °C. Under optimal conditions, the yield of 5-CQA and CAF were 2.00 and 6.26 mg g-1, respectively. Theophylline, caffeic acid, and total chlorogenic acid concentrations were 0.53, 0.06 e 4.40 mg g-1, respectively and 9 chlorogenic acids were identified in the extract. The extract showed considerable antioxidant capacity, with efficient concentration value of 46,87 mg L-1 in the DPPH assay and 152,71 μM FeSO4 g-1 (FRAP) and high toxicity. The developed extraction methodology showed similar performance as solid-liquid extraction to 5-CQA yield.
5

Recuperação de compostos bioativos do resíduo do processamento do café (silverskin) : otimização do processo de extração; caracterização química, capacidade antioxidante e toxicidade dos extratos

Santos, Anai Loreiro dos January 2018 (has links)
O silverskin é um resíduo, rico em compostos antioxidantes, como o ácido 5-cafeoilquínico (5-CQA) e a cafeína (CAF), produzido durante a torrefação dos grãos de café. O objetivo deste estudo foi desenvolver uma metodologia de extração, aliando a extração assistida por ultrassom e o planejamento de experimentos, para a recuperação simultânea do 5-CQA e da CAF da silverskin. Os extratos gerados foram caracterizados e tiveram a capacidade antioxidante e a toxicidade investigadas. A metodologia de superfície de resposta e a função Desejabilidade foram empregadas na otimização da extração. A LC-DAD/MSn foi utilizada para a caracterização dos extratos, os métodos de sequestro do radical DPPH e de redução do ferro (FRAP), para avaliar a capacidade antioxidante; enquanto o ensaio da Artemia salina foi usando para avaliar a toxicidade. As condições ótimas de extração foram: 45 % de etanol em água como solvente de extração, razão amostra-solvente 1/20, extração por 7 min a 59 °C, com rendimentos de 5-ACQ e CAF de respectivamente 2,00 e 6,26 mg g-1. No total, 9 derivados clorogênicos foram tentativamente identificados. Os teores de teofilina, ácido cafeico e derivados clorogênicos foram respectivamente: 0,53, 0,06 e 4,40 mg g-1. O extrato demonstrou considerável capacidade antioxidante, com concentração eficiente de 46,87 mg L-1 e capacidade redutora de ferro de 152,71 μM de FeSO4 g-1, além de alta toxicidade. O método desenvolvido obteve rendimento similar ao da extração sólido-líquido para o 5-ACQ. / Silverskin is a waste generated during the coffee beans roasting. This residue has been showing antioxidant compounds, mainly 5-caffeoylquinic acid (5-CQA) and caffeine (CAF). The aim of this study was used the design of experiments and ultrasound-assisted extraction to develop an extraction method for the efficient recovery of 5-CQA and CAF from silverskin, simultaneously. In addition, the optimized extract was characterized, and its antioxidant capacity and acute toxicity were investigated. The response surface methodology and Desirability function were employed to optimize the extraction. The chemical characterization was carry out by LC-DAD/ESI-MSn. Antioxidant capacity was evaluated by DPPH (2, 2-diphenyl-1 picryl hydrazyl) and FRAP (ferric reducing antioxidant power) methods and the acute toxicity by Artemia salina assay. The optimal extraction conditions were 45.0 % ethanol in water, the solid-to-liquid ratio was 1:20, and extraction for 7.0 min at 59 °C. Under optimal conditions, the yield of 5-CQA and CAF were 2.00 and 6.26 mg g-1, respectively. Theophylline, caffeic acid, and total chlorogenic acid concentrations were 0.53, 0.06 e 4.40 mg g-1, respectively and 9 chlorogenic acids were identified in the extract. The extract showed considerable antioxidant capacity, with efficient concentration value of 46,87 mg L-1 in the DPPH assay and 152,71 μM FeSO4 g-1 (FRAP) and high toxicity. The developed extraction methodology showed similar performance as solid-liquid extraction to 5-CQA yield.
6

Polyphénols d’agrumes (flavanones) : extraction de glycosides de la peau d’orange, synthèse de métabolites chez l’homme (glucuronides) et étude physico-chimique de leur interaction avec la sérum albumine / Citrus polyphenols (flavanones) : extraction of glycosides from orange peel, synthesis of metabolites (glucuronides) found in human and a physico-chemical study to investigate their interaction with human serum albumin

Khan, Muhammad Kamran 15 November 2010 (has links)
Un groupe d'études épidémiologiques fournit une bonne preuve de la relation inverse associé à la consommation de fruits et légumes et les maladies chroniques important comme maladies cardiovasculaires et certains types de cancers. Après les longues années d'études sur phytomacronutrients, le rôle de phytomicronutrients tels que les polyphénols est désormais très étudiée et appréciée dans le contrôle de ces maladies dégénératives. La présente étude combine les études d'extraction, de synthèse et d'analyse sur les principaux polyphénols des fruits d'agrumes, FLAVANONES. Connaissance de nutritionnels et de santé a augmenté la production d'agrumes en provenance des dernières décennies. Ces productions plus générer des bye-produits. Pour leur utilisation alternative à des antioxydants extraits riches, l'extraction assistée par ultrasons (UAE) des polyphénols en particulier flavanones de l'orange (Citrus sinensis L.) par son peau en utilisant l'éthanol comme solvant de qualité alimentaire a été prouvé son efficacité en comparaison avec la méthode conventionnelle . Un plan composite central (CCD) a révélé que l'approche des conditions optimisées pour UAE ont une température de 40 ° C, une puissance de 150W sonication et un 4:1 (v / v) d'éthanol: ratio de l'eau. En outre, l'activité antioxydante déterminée par les tests DPPH et ORAC a confirmé la pertinence des UAE pour la préparation d'extraits de plantes riches en antioxydants.Les glucuronides de flavanone sont les principaux métabolites phénoliques détectés dans le plasma humain après la consommation d'agrumes. Jusqu'à maintenant, toutes les études sur les cellules liées au cancer ou les maladies cardiovasculaires ont été réalisées soit sur les aglycones ou sur leurs glycosides. Par conséquent, il ya grand besoin de glucuronides flavanone pure pour démontrer le potentiel réel de flavanones dans la prévention de ces maladies. Dans ce travail, glucuronides de naringénine (4'- et 7-O-β-D-glucuronides) et de hespérétine (3'- et 7-O-β-D-glucuronides), les aglycones flavanone majeur dans le pamplemousse et d'orange, respectivement, ont été synthétisés chimiquement par une protection et la déprotection sélective des groupements d'acide glucuronique et de flavanone. La caractérisation structurale complète de composés purifiés a été réalisée par résonance magnétique nucléaire et spectrométrie de masse.L'affinité des quatre glucuronides pour l'albumine sérum d’humaine (HSA) a été testée par leur capacité à éteindre la fluorescence intrinsèque de HSA (Trp, seul résidu de sous-domaine IIA). Leurs constantes de fixation (K) ont été estimées de l'ordre de 30 à 60 × 103 M-1 et comparées à celles de l'aglycones (70 à 90 × 103 M-1). Les enquêtes de la liaison compétitive ou non compétitive de la glucuronides dans la présence de sondes fluorescentes (sarcosine dansyl) nous a permis d'obtenir un aperçu dans les sites de liaison. L'étude a également été étendue aux chalcones hespérétine et naringénine (synthétisés en utilisant des conditions alcalines optimisée), qui sont les précurseurs de biosynthèse des flavanones / A bunch of epidemiological studies provides good evidence on the inverse relationship associated with the consumption of fruits and vegetables and the chronic diseases importantly cardiovascular diseases and some types of cancers. After the long years of study on phytomacronutrients, the role of phytomicronutrients such as polyphenols is now highly studied and appreciated in the control of such degenerative diseases. The present study combines the extraction, synthetic and analytical studies on the major polyphenols of citrus fruits, FLAVANONES.Awareness of nutritional and health facts has increased the production of citrus fruits from last few decades. These higher productions generate higher by-products. For their alternative utilisation to have antioxidants rich extracts, the ultrasound-assisted extraction (UAE) of polyphenols especially flavanones from orange (Citrus sinensis L.) peel by using ethanol as afood grade solvent has been proved its efficiency when compared with the conventional method. A central composite design (CCD) approach revealed that the optimized conditions for UAE were a temperature of 40°C, a sonication power of 150W and a 4:1 (v/v) ethanol:water ratio. Furthermore, the antioxidant activity determined by the DPPH and ORAC tests confirmed the suitability of UAE for the preparation of antioxidant-rich plant extracts. Flavanone glucuronides are the major phenolic metabolites detected in human plasma after consumption of citrus fruits. Up to now all cell studies related to cancer or cardiovascular diseases were conducted either on the aglycones or on their glycosides. Hence, there is great need of pure flavanone glucuronides to demonstrate the real potential of flavanones in the prevention of these diseases. In this work, glucuronides of naringenin (4′- and 7-O-β-D-glucuronides) and hesperetin (3′- and 7-O-β-D-glucuronides), the major flavanone aglycones in grapefruit and orange respectively, have been chemically synthesized by selective protection and deprotection of flavanone and glucuronic acid moieties. The complete structural characterisation of purified compounds were realised by nuclear magnetic resonance and mass spectrometry.The affinity of the four glucuronides for human serum albumin (HSA) was tested via their ability to quench the intrinsic fluorescence of HSA (single Trp residue in sub-domain IIA). Their binding constants (K) were estimated in the range of 30 – 60 × 103 M-1 and compared with those of the aglycones (70 – 90 × 103 M-1). Investigations of competitive or noncompetitive binding of the glucuronides in the presence of fluorescent probes (dansyl sarcosine) allowed us to get some insight in the binding sites. The study was also extended to the hesperetin and naringenin chalcones (synthesised using optimized alkaline conditions), which are the biosynthetic precursors of flavanones
7

Isolamento de polissacarí­deos não amiláceos da banana (musa cavendishii L. variedade Nanicão) e seu potencial uso como ingrediente funcional. / Isolation of non-starch polysaccharides from banana Cavendishii L. variety Nanicão) and its potential use as a functional ingredient.

Rayo Mendez, Lina Maria 19 July 2018 (has links)
Neste trabalho, polissacarídeos não amiláceos (PNAs) da banana madura com potencial de propriedades imunomoduladoras foram obtidos por meio da remoção dos açúcares solúveis (glicose, frutose e sacarose) do purê de banana submetido a duas técnicas de extração: sólido-líquido (ESL) com agitação mecânica e assistida por ultrassom (EAU) usando etanol a 99,5 g/100 g como solvente. Para o estudo em batelada, diferentes razões da matéria-prima/solvente (1:5, 1:7 e 1:10) g/mL, tempos de extração (30, 60 e 90) min e duas temperaturas de (25 e 65) °C foram estudados. No estudo cinético, o impacto da redução da razão matéria-prima/solvente de 1:5 para 1:3 g/mL foi estudado até 90 min, nas mesmas condições estudadas na extração em batelada. O teor de açúcares solúveis (AS) medido nos extratos foi superior na temperatura de 65°C, porém às razões de 1:7 e 1:10, não resultou em maior quantidade de AS nos extratos, portanto, menores quantidades de etanol podem ser usadas diminuindo custos. Com o emprego da técnica EAU à 25 °C e tempo de extração de 30 min, foi observado que uma redução da razão matéria-prima/solvente até 1:3 g/mL produz maior rendimento de processo. No entanto, foi observado que maiores tempos de extração promoveram degradação da parede celular da matéria-prima. Entre os modelos cinéticos testados, o ajuste do modelo de Patricelli aos dados experimentais indicou que a ESL é regida pela fase de lavagem em que ocorreu 85 % da extração dos AS. Frações molares de glicose, ácidos galacturônicos, manose, arabinose, xilose, galactose de conteúdo monossacarídeo foram observadas nos rafinados, indicando possivelmente serem parte de polissacarídeos do tipo ?-glicanos, xilomananos glucomananos, arabinogalactanos e arabinoxilanos. / In this work, non-starch polysaccharides (PNAs) of ripe bananas with potential for immunomodulatory properties were obtained by means removing the soluble sugars (glucose, fructose and sucrose) from banana puree submitted to two extraction techniques: solid-liquid (SLE) with mechanical stirring and ultrasonic assisted (UAE) using 99.5 g/ 100 g ethanol as solvent. For the batch study, different ratios of the raw material/ solvent (1:5, 1:7 and 1:10) g/ mL, extraction times of (30, 60 and 90) min and two temperatures of (25 and 65 ) °C were studied. In the kinetic study, the impact of reducing the raw material/ solvent ratio from 1:5 to 1:3 g/ mL was studied up to 90 min, under the same conditions studied in batch extraction. The soluble sugar content (AS) measured in the extracts was higher at temperature of 65 °C, however, at the ratios of 1:7 and 1:10, did not result in higher amount of AS in the extracts, therefore, smaller amounts of ethanol can be costs. With the use of the UAE technique at 25 °C and extraction time of 30 min, it was observed that a reduction of the raw material / solvent ratio up to 1:3 g / mL produces a higher process yield. However, it was observed that longer extraction times promoted degradation of the cell wall of the raw material. Among the kinetic models tested, the adjustment of Patricelli model to the experimental data indicated that the SLE the predominance is by the washing phase in which 85% of the AS extractions occurred. Glucose molar fractions, galacturonic acids, mannose, arabinose, xylose, galactose of monosaccharide content were observed in the raffinates, indicating possibly being part of polysaccharides as ?-glycan, xylomannans, glucomannans, arabinogalactans and arabinoxylans.
8

Bioactive extracts of Olea europaea waste streams : a thesis presented in partial fulfilment of the requirements for the degree of Master of Technology in Food Technology at Massey University

Mossop, Nicholas Paul January 2006 (has links)
The production of olive oil has seen an increase in recent years due to a broader understanding of the health benefits of the Mediterranean Aliment Culture. With this expanding industry we also see an increase in the waste products associated with olive oil production. Given the high polluting content of the waste streams and the economic costs associated with its removal and processing, waste remediation and disposal has become a significant point of interest for both producers and local bodies. In this project, wastes of the olive oil production industry are examined for their use as the raw material for a novel product used in the control of horticulturally important diseases, examining the effect of extraction protocols on the activity of the final product. Active fractions of the olive oil wastes were identified from literature and protocols for their extraction and recovery developed; incorporating both standard solvent extraction and novel ultrasound-assisted extraction. Criteria for the analysis of extract quality were outlined and potential target applications identified. The biophenolic compounds of olive wastes were identified as providing the majority of the active fraction, so protocols were developed for the recovery of these compounds. Standard solvent extraction and ultrasound-assisted extraction were examined for their effectiveness of biophenolic recovery and their effect on product quality. Certain horticulturally important diseases were identified as potential targets, and bioassays undertaken to determine the ability of a crude extract to inhibit and control these diseases. It was found that the action of ultrasound during extraction provides a greater degree of recovery of biophenolic compounds, with minimal loss of product quality; as determined by bioassays and total biophenol determination. This increase in recovery is due primarily to the destruction of cellular material resulting in higher rates and absolute yields of recovery. This work provides evidence of the occurrence of some interesting phenomenon in the recovery of biophenols from olive wastes that deserves further examination. The crude olive leaf extract was shown to have an inhibitory effect on bacteria and effectively no inhibitory effect on fungal species in the total biophenol ranges tested. Erwinia amylovora and Staphylococcus aureus both showed a large susceptibility to the olive leaf extract. Results showed a higher degree of susceptibility of Gram positive bacteria and a potential resistance in soil microbes. For bacterial species, total biophenol concentrations of 0.15 to 3.50 mg GAE/ml provided inhibitory effects, while with the fungal species tested, no inhibitory effects were found at total biophenol concentrations of up to 2.50 mg GAE/ml. Some evidence exists that there is an opportunity for the economic recovery of olive biophenols for use as a novel product, but more work is required to determine specific applications and/or targets of use, as well as optimisation of the extraction and purification protocol. A sample removed from interfering compounds will allow the examination of activity of particular compounds and hence a better understanding of the action of the olive waste extract.
9

Isolamento de polissacarí­deos não amiláceos da banana (musa cavendishii L. variedade Nanicão) e seu potencial uso como ingrediente funcional. / Isolation of non-starch polysaccharides from banana Cavendishii L. variety Nanicão) and its potential use as a functional ingredient.

Lina Maria Rayo Mendez 19 July 2018 (has links)
Neste trabalho, polissacarídeos não amiláceos (PNAs) da banana madura com potencial de propriedades imunomoduladoras foram obtidos por meio da remoção dos açúcares solúveis (glicose, frutose e sacarose) do purê de banana submetido a duas técnicas de extração: sólido-líquido (ESL) com agitação mecânica e assistida por ultrassom (EAU) usando etanol a 99,5 g/100 g como solvente. Para o estudo em batelada, diferentes razões da matéria-prima/solvente (1:5, 1:7 e 1:10) g/mL, tempos de extração (30, 60 e 90) min e duas temperaturas de (25 e 65) °C foram estudados. No estudo cinético, o impacto da redução da razão matéria-prima/solvente de 1:5 para 1:3 g/mL foi estudado até 90 min, nas mesmas condições estudadas na extração em batelada. O teor de açúcares solúveis (AS) medido nos extratos foi superior na temperatura de 65°C, porém às razões de 1:7 e 1:10, não resultou em maior quantidade de AS nos extratos, portanto, menores quantidades de etanol podem ser usadas diminuindo custos. Com o emprego da técnica EAU à 25 °C e tempo de extração de 30 min, foi observado que uma redução da razão matéria-prima/solvente até 1:3 g/mL produz maior rendimento de processo. No entanto, foi observado que maiores tempos de extração promoveram degradação da parede celular da matéria-prima. Entre os modelos cinéticos testados, o ajuste do modelo de Patricelli aos dados experimentais indicou que a ESL é regida pela fase de lavagem em que ocorreu 85 % da extração dos AS. Frações molares de glicose, ácidos galacturônicos, manose, arabinose, xilose, galactose de conteúdo monossacarídeo foram observadas nos rafinados, indicando possivelmente serem parte de polissacarídeos do tipo ?-glicanos, xilomananos glucomananos, arabinogalactanos e arabinoxilanos. / In this work, non-starch polysaccharides (PNAs) of ripe bananas with potential for immunomodulatory properties were obtained by means removing the soluble sugars (glucose, fructose and sucrose) from banana puree submitted to two extraction techniques: solid-liquid (SLE) with mechanical stirring and ultrasonic assisted (UAE) using 99.5 g/ 100 g ethanol as solvent. For the batch study, different ratios of the raw material/ solvent (1:5, 1:7 and 1:10) g/ mL, extraction times of (30, 60 and 90) min and two temperatures of (25 and 65 ) °C were studied. In the kinetic study, the impact of reducing the raw material/ solvent ratio from 1:5 to 1:3 g/ mL was studied up to 90 min, under the same conditions studied in batch extraction. The soluble sugar content (AS) measured in the extracts was higher at temperature of 65 °C, however, at the ratios of 1:7 and 1:10, did not result in higher amount of AS in the extracts, therefore, smaller amounts of ethanol can be costs. With the use of the UAE technique at 25 °C and extraction time of 30 min, it was observed that a reduction of the raw material / solvent ratio up to 1:3 g / mL produces a higher process yield. However, it was observed that longer extraction times promoted degradation of the cell wall of the raw material. Among the kinetic models tested, the adjustment of Patricelli model to the experimental data indicated that the SLE the predominance is by the washing phase in which 85% of the AS extractions occurred. Glucose molar fractions, galacturonic acids, mannose, arabinose, xylose, galactose of monosaccharide content were observed in the raffinates, indicating possibly being part of polysaccharides as ?-glycan, xylomannans, glucomannans, arabinogalactans and arabinoxylans.
10

DESENVOLVIMENTO E APLICAÇÃO DE METODOLOGIA ANALÍTICA (CLAE/FL) PARA DETERMINAÇÃO DE FLUOROQUINOLONAS EM SEDIMENTO ESTUARINO DA ILHA DO MARANHÃO / DEVELOPMENT AND APPLICATION OF ANALYTICAL METHODS (HPLC / FL) FOR DETERMINATION OF FLUOROQUINOLONES IN ESTUARINESEDIMENT OF ISLAND OF MARANHÃO

Neves, Mônica Araujo das 19 December 2014 (has links)
Made available in DSpace on 2016-08-19T12:56:49Z (GMT). No. of bitstreams: 1 Dissertacao Monica de Araujo Neves.pdf: 1987787 bytes, checksum: c4159e188bd8d08a6860a3f310618950 (MD5) Previous issue date: 2014-12-19 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Drugs in the planet have increased during last decades. Such compounds can cause adverse impact on ecosystems. Soon, more effective analytical methods are essential for the study of new pollutants, especially in magazines whose headquarters are very complex as mangrove sediments. Therefore, this study aimed to improve an analytical method to assess the occurrence of fluoroquinolone antibiotics, ciprofloxacin (CIP), levofloxacin (LEV) and norfloxacin (NOR), in sediment samples from the Paciência river located on the Maranhão island using the technique of ultrasound-assisted extraction, extraction phase solid and liquid chromatography (HPLC/FD). According to the study, the method was linear (r²> 0.99), recovery ranging from 73.73 to 88.85%, precise (RSD <20%), selective and sensitive (detection limit for CIP, LEV and NOR 9.32; 17.78 and 4.42 µg.kgˉ¹, respectively, and limit of quantitation of 20 µg.kgˉ¹ for all three drugs) for quantification of fluoroquinolones in estuarine sediments. Other relevant aspects of the method developed in this work were the simplicity, low cost and absence of interfering to a very complex environmental matrix as are the mangrove sediments. When evaluating the sediment at various points of the river there was contamination at three points by CIP ranging from 56.55 to 70.45 µg.kgˉ¹ These results are similar to those found around the planet to polluted regions and they are of concern due to the effects of these antibiotics in the ecosystem. / É crescente a utilização de fármacos no planeta nas últimas décadas. Tais compostos podem causar impacto negativo nos ecossistemas. Logo, métodos analíticos mais eficazes são fundamentais para o estudo de novos poluentes, especialmente em compartimentos cujas matrizes são muito complexas como sedimentos de manguezal. Sendo assim, este trabalho teve por objetivo aprimorar um método analítico para avaliar a ocorrência de antibióticos fluoroquinolônicos, ciprofloxacino (CIP), levofloxacino (LEV) e norfloxacino (NOR), em amostras de sedimento do rio Paciência localizadas na ilha do Maranhão utilizando a técnica de extração assistida por ultrassom, extração em fase sólida e a cromatografia líquida (CLAE/FL). Segundo o estudo, o método mostrou-se linear (r²>0,99), recuperação variando 73,73-88,85%, preciso (DPR < 20%), seletivo e sensível (Limite de detecção para CIP, LEV e NOR de 9,32; 17,78 e 4,42 µg.kgˉ¹, respectivamente e limite de quantificação de 20 µg.kgˉ¹ para todos os três analitos) para quantificação de fluoroquinolonas em sedimento estuarino. Outros aspectos relevantes do método desenvolvido nesse trabalho foram à simplicidade, o baixo custo e ausência de interferentes para uma matriz ambiental muito complexa como são os sedimentos de manguezal. Ao avaliar o sedimento em vários pontos do rio observou-se contaminação em três pontos por CIP variando entre 56,55 70,45 µg.kgˉ¹. Esses resultados são similares ao encontrados ao redor do planeta para regiões poluídas e são motivos de preocupação em função dos efeitos desses antibióticos no ecossistema.

Page generated in 0.1093 seconds