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Reposicionamento de fármacos no câncer de boca: Identificação de possíveis agentes / Drug repositioning for oral cancer: Identifying candidate therapeutic agentsKellen Cristine Tjioe 07 August 2015 (has links)
Objetivos: O objetivo deste estudo foi o de identificar compostos seletivamente tóxicos ao carcinoma espinocelular de boca in vitro por meio do reposicionamento de fármacos. Material e Métodos: Por meio de um escaneamento baseado na viabilidade celular de 1.280 fármacos, nós selecionamos três princípios ativos (luteolin, metixene hydrochloride e nitazoxanide) letais às células de câncer de boca SCC-25 e pouco tóxicos às células de queratinócitos cutâneos imortalizados HaCaT. Os fármacos candidatos foram investigados quanto à sua dose- e tempo-resposta bem como comparados e combinados à agentes quimioterápicos padrão por meio do ensaio por colorimetria com brometo de tiazolil azul de tetrazolio (MTT). O impacto dos fármacos na motilidade do SCC-25 e do HaCaT foi verificado pelo ensaio de migração celular e seus mecanismos de ação também foram explorados por meio da verificação dos níveis das proteínas fosforiladas pelo western blotting. Todos os experimentos foram realizados em triplicata e, pelo menos, três vezes independentes. O teste t de student foi utilizado para confrontar as variáveis e nível de significância de 5% foi estabelecido para todos os testes. Resultados: O flavonoide natural luteolin exerceu citotoxicidade potente contra as células de câncer de boca in vitro, apresentando baixa toxicidade ao HaCaT e alta eficiência quando comparado a quimioterápicos como a cisplatina e o AG1478. Do ponto de vista molecular, a luteolin ativou a via de sinalização do dano do DNA e, combinada com um inibidor do Chk, apresentou efeitos potencializados. Além disso, nós demonstramos que a nitazoxanide e o metixene hydrochloride são capazes de destruir células SCC-25 porém não as HaCaT de maneira proporcional à dose e ao tempo de tratamento. As combinações entre os três fármacos hit e com a cisplatina ou o AG1478 potencializaram seus efeitos contra as células malignas. Conclusões: O presente estudo traz a luteolin, o metixene hydrochloride e a nitazoxanide como fortes candidatos a agentes terapêuticos contra o câncer de boca uma vez que estes compostos apresentam maior eficácia contra células de câncer de boca e menor toxicidade contra células não tumorais in vitro do que agentes quimioterápicos convencionais. / Objectives: Here we aimed at identifying and reposition approved drugs that could be selectively toxic towards oral squamous cell carcinoma cells. Materials and Methods: Through a cell-based drug screening of 1,280 chemical molecules, we selected 3 compounds (luteolin, metixene hydrochloride, and nitazoxanide) lethal to oral cancer SCC-25 cells, while sparing immortalized keratinocyte HaCaT cells. The drugs were then further challenged for their time- and dose-responses, as well as their comparison and combination to standard chemotherapeutic agents by colorimetric assay 1-(4,5-Dimethylthiazol-2-yl)-3,5-diphenylformazan, Thiazolyl blue formazan (MTT). The impact on SCC-25 and HaCaT motility as well as the mode of action of the drugs was then further explored by scratching assay and western blotting, respectively. All the experiments were performed in triplicated and, at least, three independent times. Students t test was performed to verify the differences among the variables and the level of significance was set at 5%. Results: The natural flavonoid luteolin was a potent cytotoxic agent against oral cancer cells in vitro, presenting low toxicity against HaCaT cells and high efficiency as compared to standard-of-care, such as cisplatin and AG1478. From a molecular standpoint, luteolin coopted the DNA-damage pathway and could be efficiently combined with Chk pharmacological inhibitor. Moreover, we demonstrated that nitazoxanide and metixene hydrochloride kill the SCC-25 but not the HaCaT cells in a dose- and time-dependent. The combinations among the three drugs hit and with cisplatin and AG1478 improved their effect against the malignant cells. Conclusions: Luteolin, metixene hydrochloride, and nitazoxanide emerge as strong cytotoxic and/or adjuvant therapy in oral cancer, as these compounds present higher efficiency and lower toxicity against oral cancer cells in vitro than conventional chemotherapeutic agents.
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Aspects of the gastrointestinal uptake and metabolism of luteolin derivatives from Artemisia afra aqueous extract (preclinical)Mukinda, James Tshikosa January 2011 (has links)
<p>The aim of this study was to investigate the effect the plant matrix and the structure of the flavonoid (i.e. whether aglycone or glycoside) may have on the gastrointestinal uptake and metabolism of luteolin derivatives from Artemisia afra traditional plant medicine. Specifically, how these two factors influenced the intestinal uptake and disposition of luteolin derivatives in pure and in Artemisia afra plant extract forms were to be assessed by investigating the uptake and metabolism of the luteolin derivatives in human intestinal epithelial Caco-2 cells and the perfused rat intestinal loop. To realize this aim, the following were determined: (1) identification and characterization of major luteolin derivatives found in Artemisia afra, (2) the effect of the plant matrix on the uptake of luteolin derivatives in Artemisia afra aqueous-extract forms across the Caco-2 cell monolayer, (3) the effect of the plant matrix on the absorption and metabolism of luteolin derivatives in Artemisia afra aqueous-extract forms in the perfused rat small intestine, (4) the effect of gut contents on the uptake and metabolism of luteolin derivatives in intestinal loop and (5) the metabolic profiles of luteolin derivatives obtained for the pure solutions versus plant aqueous extract solutions in Caco-2 cells and the rat intestine.</p>
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Aspects of the gastrointestinal uptake and metabolism of luteolin derivatives from Artemisia afra aqueous extract (preclinical)Mukinda, James Tshikosa January 2011 (has links)
<p>The aim of this study was to investigate the effect the plant matrix and the structure of the flavonoid (i.e. whether aglycone or glycoside) may have on the gastrointestinal uptake and metabolism of luteolin derivatives from Artemisia afra traditional plant medicine. Specifically, how these two factors influenced the intestinal uptake and disposition of luteolin derivatives in pure and in Artemisia afra plant extract forms were to be assessed by investigating the uptake and metabolism of the luteolin derivatives in human intestinal epithelial Caco-2 cells and the perfused rat intestinal loop. To realize this aim, the following were determined: (1) identification and characterization of major luteolin derivatives found in Artemisia afra, (2) the effect of the plant matrix on the uptake of luteolin derivatives in Artemisia afra aqueous-extract forms across the Caco-2 cell monolayer, (3) the effect of the plant matrix on the absorption and metabolism of luteolin derivatives in Artemisia afra aqueous-extract forms in the perfused rat small intestine, (4) the effect of gut contents on the uptake and metabolism of luteolin derivatives in intestinal loop and (5) the metabolic profiles of luteolin derivatives obtained for the pure solutions versus plant aqueous extract solutions in Caco-2 cells and the rat intestine.</p>
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Conventional Breeding and Molecular Techniques to Improve Phytochemical Concentrations in Pepper (Capsicum spp.)Butcher, Justin 2011 December 1900 (has links)
Five separate field experiments were conducted across different environmental locations in Texas for the purpose of quantifying concentrations of different phytochemical groups (ascorbic acid, capsaicinoids, and flavonoids) within various pepper species, as well as, to identify the most optimum environment to promote expression of the aforementioned phytochemical. Depending on the particular experiment, quantitative measurements were then used in more detail in one of three ways: for identification of the most superior individuals and optimum environmental locations to express elevated concentrations of a particular phytochemical (first three experiments), to calculate heritability and % heterosis estimates for various fruit characteristics and phytochemical levels (fourth experiment), or for use in a specific biotechnology technique to potentially identify a molecular marker linked to elevated levels of ascorbic acid (AA) and flavonoids (quercetin and luteolin) (fifth experiment). In the first experiment, significant differences in fruit weight, capsaicin, and dihydrocapsaicin (DHC) were revealed in fruit tissue of five Habanero (Capsicum chinense) hybrids in comparison to a popular, commercial check (Kukulkan F1) after being grown across three different environmental locations (College Station, Uvalde, and Weslaco). Fruit grown at the Weslaco location was found to be larger and contained more capsaicin and DHC than those produced in Uvalde or College Station. While flavonoid contents were variable and low in all genotypes and locations, a few hybrids showed some potential for use in future crossing schemes to compete against the commercial check. Our results further suggested that variation in phytochemicals in fruit tissue of Habanero genotypes can be exploited by selecting in an appropriate environment. In the second experiment, analysis of four jalapeño hybrids in comparison to three commercial checks (Dragon, Ixtapa, and J1845), as well as, two cayenne hybrids in comparison to one commercial check (Mesilla) were compared after growing in three different locations (Amarillo, College Station, and Uvalde). Results demonstrated that the College Station location contributed to production of fruit containing higher concentrations of both AA and flavonoids, while those grown in Amarillo produced fruit with higher capsaicinoids. As expected, cayenne samples contained more AA and flavonoids than jalapeño samples. In comparison to the commercial jalapeño checks, all jalapeño hybrids generally expressed less capsaicinoids. With respect to AA and flavonoid concentrations, a few jalapeño hybrids proved to have some potential to compete against their respective commercial cultivars. For the cayenne market, one genotype revealed its potential use in mild markets and for farmers interested in a new hybrid expressing both appreciable levels of phytochemicals, as well as, more visually aesthetic attributes. Statistical analyses from the third experiment found all the F-values for each characteristic to be significant except the Location x Genotype (L x G) component for fruit wall thickness. For this experiment, a total of 21 different C. annuum (jalapeño, Serrano, and cayenne) genotypes were evaluated after growing in two diverse environmental locations (Uvalde and Weslaco). In general, peppers grown in Weslaco produced fruit with higher concentrations of AA and capsaicinoids, with a few exceptions, while fruit grown at Uvalde generally was larger in size and contained higher concentrations of flavonoids. In comparison to their respective commercial checks (jalapeño – Dragon, Tormenta; Serrano – Halcon, Magnum45; cayenne – Mesilla), a few hybrids were arguably more desirable for their respective markets with respect to different fruit measurements, AA, capsaicinoid, and flavonoid concentrations. This evidence further suggested the potential benefit this material could have for growers interested in replacing current material in the industry and to more successfully provide consumers with a healthier ingredient to better sustain their lives. In the fourth experiment, results confirmed our hypotheses that paprika type material has higher AA and flavonoid concentrations than Serrano peppers, while the opposite is possible for capsaicinoid expression. For this experiment, our goal was to identify the relative ease of incorporating different traits of interest into an improved specimen evaluating a combination of 29 F1 paprika and Serrano pepper (C. annuum) hybrids along with 19 of their respective parents. We were also able to identify how productive certain crossing combinations were at expressing a significant amount of positive heterosis for different characteristics of interest. From our correlation analyses, we were able to identify that a significant association can exist between fruit weight and fruit diameter, as well as when other characteristics were evaluated. In all, our results were able to reveal how effective certain combinations of parent material are towards production of offspring with improved traits expressing appreciable fruit characteristics and elevated phytochemical concentrations. Finally, the quantitative measurements produced in our F2 molecular marker experiment found significant amounts of variation for both flavonoids (quercetin and luteolin) and AA expression. It was evident that incorporation of the necessary genes of interest present within fruit tissue across this F2 family for these different phytochemicals were passed from ‘Ca377’ (P1) to several of these offspring. Three candidate primers were eventually identified for their potential polymorphic expression. However, after statistically analyzing the results, only one primer was identified as expressing a significant association (although the value was still relatively low) of variability with respect to luteolin. We also identified a significant association between quercetin and luteolin, quercetin and total flavonoids (quercetin+luteolin), as well as, luteolin and total flavonoids (quercetin+luteolin) in fruit tissues of different pepper material. From our results, we were able to arguably conclude that an environmental component may serve a more essential role in activating the necessary physiological processes to produce specific secondary metabolites. Although our RAPD technique was fairly straightforward and useful, some may argue that a more reliable technique would have been better. Therefore, we postulate that success may be possible in the near future if a different molecular marker technique is used.
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Maternal Immune Dysregulation in the Pathogenesis of Neurodevelopmental Disorders: Interleukin-6 as a Central Mechanism and Therapeutic Target of FlavonoidsParker-Athill, Ellisa Carla 01 January 2012 (has links)
Activation of the maternal immune system and resultant maternal cytokine expression due to prenatal infection has been implicated as a significant contributor to the pathology of neuropsychiatric and neurodevelopmental disorders such as schizophrenia and Autism Spectrum Disorder (ASD). Increased maternal interleukin-6 (IL-6) expression, observed clinically and in animal models of prenatal infection, and resultant activation of key signaling pathways, has been shown to be a biological indicator of pathology, and a central component of the pathological mechanism. In animal models of prenatal infection and clinically in pregnancy disorders hallmarked by immunological irregularities and increased IL-6 expression, inhibition of IL-6 has been shown to reduce pathological symptoms both maternally and in the exposed offspring. This study aims to demonstrate the ability of IL-6 expression, resulting from prenatal infection, to induce neuropathological and behavioral outcomes that mirror clinical observations seen in disorders such as ASD. More importantly, it shows how flavones luteolin and diosmin, a subclass of the flavonoid family, through inhibition of IL-6 mediated activation of Signal Transducer and Activator of Transcription-3 (Stat3) can reduce these pathologies both in vitro and in vivo.
Evidence suggests that flavonoids, a polyphenolic class of naturally occurring plant secondary metabolites, are potent anti-inflammatory agents that can attenuate the expression of cytokines such as IL-6, possibly through the modulation of tyrosine kinase activity. They have been shown to have significant therapeutic potential in disorders hallmarked by increased inflammation or disruptions in immune regulation, such as neurodegenerative disorders and certain cancers. Members such as diosmin have also been shown to be safe during pregnancy, and are currently utilized in the treatment of certain vascular disorders associated with pregnancy.
In vitro work undertaken in this study showed that co-administration of luteolin with IL-6 in neural stem cells (NSC) was able to attenuate pathological outcomes induced by IL-6 including aberrant proliferation, over expression of astroglial marker, glial fibrillary acidic protein (GFAP) and changes in cellular morphology. In vivo studies involving luteolin and diosmin further confirmed the therapeutic efficacy of these compounds as similar attenuation of IL-6 mediated maternal and fetal pro-inflammatory cytokine expression and abnormal behaviors in prenatally exposed offspring was observed. Mechanistically, these effects were mediated through inhibition of Stat3 activation although other pathways activated by IL-6 were modulated by flavone co-treatment. Flavonoid treatment during periods of prenatal infection may prove to be a therapeutic intervention for the resultant pathological outcomes seen in offspring through attenuation of the maternal and fetal immune response to infection as well as modulation of signaling pathways in the fetal brain. These compounds may prove therapeutically efficacious for the application in perinatal conditions hallmarked by increased inflammation during pregnancy.
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Obsah vybraných fenolických látek v kořeninových rostlinách. / Content of selected phenolic compounds in spice plants.BERANOVÁ, Zuzana January 2013 (has links)
This work concerns the amount of certain phenols in some of the representatives of families Alliaceae, Lamiaceae and Apiaceae. Phenols in plants are widely represented and highly concentrated. Flavonoids are one of the smallest, yet quite significant classes of phenols. Ingestion of food containing flavonoids can prevent certain diseases such as Arteriosclerosis. cardiovascular and tumor diseases. This work focuses, for their special biological effects, on five flavonoids: Kaempferol, Quercetin, Myricetin, Apigenin and Luteolin. For determining the content of phenols a method of High-performance liquid chromatography (HPLC) was used. Three representative of the family Alliaceae, two representatives of the family Lamiaceae and three representatives of the family Apiaceae were analysed. Only edible parts of the plants were used for the analysis and the amount of phenols was compared in certain plants planted in beddings to the plants planted in greenhouses. At first, the qualitative representantion of phenols was ascertained by the HPLC method. The result is chromatographic profiles, which were then used in calculating the amount of particular phenols. Then the total amounts of kaempferol, quercetin, myricetin, apigenin and luteolin were found out thanks to HPLC method. The biggest amount of total kaempferol was determined in petroselium hortense planted in beddings (588 mg/kg of fresh sample) and in a greenhouse (340 mg/kg of fresh sample). The biggest amount of quercetin was determined in red onion planted in a greenhouse (773 mg/kg of fresh sample) and in ocimum basilicum planted in beddings (535 mg/kg of fresh sample). The biggest amount of apigenin was determined in petroselium hortense planted in a greenhouse (1790 mg/kg of fresh sample) and in petroselium chrispum planted in beddings (3690 mg/kg of fresh sample).
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ASSESSMENT OF THE INFLUENCE OF PROCESSING CONDITIONS ON THE ANTIOXIDANT POTENTIAL OF EXTRACTS OBTAINED FROM OLIVE OIL INDUSTRY BYPRODUCTSAhmad-Qasem Mateo, Margarita Hussam 03 January 2016 (has links)
Tesis por compendio / [EN] The main goal of this Thesis was to determine the influence of the main processing stages involved in obtaining natural extracts with high antioxidant potential from byproducts originating in the olive oil industry.
Firstly, the effect of freezing and/or the drying methods applied to olive oil byproducts on the polyphenol content and antioxidant capacity of the extracts subsequently obtained was addressed. For this purpose, two byproducts were considered: olive leaves and olive pomace.
Secondly, the feasibility of intensifying the extraction of olive leaf polyphenols by means of a new technology, such as power ultrasound, was approached taking both compositional and kinetic issues into account.
Thirdly, how the processing conditions (drying and extraction) influence the extract's stability was evaluated. Thus, on the one hand, extracts obtained from olive leaves were subjected to in vitro digestion or dehydrated and stored at different conditions.
Finally, the possibility of obtaining a dried vegetable matrix (apple) rich in olive leaf phenolic compounds was explored by addressing the influence of apple pretreatments (blanching and freezing) and drying on the final retention of infused phenolics.
The antioxidant potential of extracts and the retention of infused polyphenols in apple were evaluated by means of the total phenolic content and antioxidant capacity analysis, as well as the identification and quantification of the main olive leaf polyphenols by HPLC-DAD/MS-MS. Moreover, in apple samples, the polyphenol oxidase and peroxidase activity and microstructure were also analyzed.
The experimental results highlighted that both drying and freezing methods significantly (p<0.05) influenced the concentration of the main polyphenols identified in the olive leaf extracts. Thus, drying at the highest temperature tested was the best processing condition in which to obtain extracts with high antioxidant capacity and phenolic content.
Ultrasound application was found to be a relevant, non-thermal way of speeding-up the antioxidant extraction from olive leaves. Thus, by appropriately tuning-up the process variables, the ultrasonic assisted extraction shortened the extraction time from the 24 h needed in conventional extraction to 15 min, without modifying either the extract composition or the antioxidant potential.
As far as extract stability is concerned, the processing conditions used for obtaining the olive leaf extracts did not have a meaningful influence on bioaccessibility. Regardless of the method used, stabilizing the extracts by means of dehydration only reduced both the antioxidant capacity and the total phenolic content by around 10 %. Moreover, storage conditions did not show a significant (p<0.05) effect on the antioxidant potential of the extracts for 28 days of storage.
A stable dried product (apple), rich in natural phenolic compounds (from olive leaves or tea extracts), was obtained by combining drying-impregnation-drying steps. However, it should be considered that the role of fresh apple drying on the retention of infused olive leaf polyphenols was more important than the further drying of the impregnated apple.
In overall terms, olive leaves can be considered a potential source of natural phenolic compounds. Notwithstanding this, the previous drying and freezing steps applied in the raw material processing are decisive factors in the obtaining of natural extracts with high antioxidant potential. Moreover, enhancing the extraction by applying power ultrasound was stated as a non-thermal way of shortening processing times. The stability of olive polyphenols during storage and in vitro digestion was closely related to the individual component considered. Finally, the exploitation of olive leaf extracts as a means of enriching solid foodstuffs requires the use of porous solid matrices free of oxidative enzymes. / [ES] El objetivo principal de esta Tesis fue determinar la influencia de las principales etapas de procesado implicadas en la obtención de extractos naturales con alto potencial antioxidante a partir de los subproductos originados en la industria del aceite de oliva.
En primer lugar, se evaluó el efecto de los métodos de congelación y/o secado de la materia prima (hojas y orujo), sobre el contenido polifénolico y la capacidad antioxidante de los extractos.
En segundo lugar, se abordó la intensificación de la extracción de polifenoles de hoja de olivo con ultrasonidos de potencia, teniendo en cuenta: composición y la cinética del proceso.
A continuación, se estudió cómo las condiciones de procesado (secado y extracción) podían influir en la estabilidad de los extractos. Así, extractos de hojas de olivo fueron sometidos a digestión in vitro o deshidratados y almacenados a distintas condiciones.
Por último, se exploró la posibilidad de obtener una matriz vegetal deshidratada (manzana) y rica en compuestos fenólicos de hoja de olivo. Para ello, se evaluó la influencia de los pretratamientos de la manzana (escaldado y congelación) y del secado en la retención final de los polifenoles impregnados.
El potencial antioxidante se determinó a través del contenido total en compuestos fenólicos y la capacidad antioxidante y la identificación y cuantificación (HPLC-DAD/MS-MS) de los principales polifenoles. Además, en manzana, se midió la actividad enzimática de la polifenol oxidasa y peroxidasa y se analizó la microestructura.
Los resultados manifestaron que el método de secado y el de congelación influyeron significativamente (p<0.05) en la concentración de los principales polifenoles en los extractos. Así, el secado a mayor temperatura resultó ser el mejor tratamiento para obtener extractos con alta capacidad antioxidante y alto contenido fenólico.
La aplicación de ultrasonidos resultó ser una alternativa no térmica muy interesante para acelerar la extracción de antioxidantes de hojas de olivo. Con la combinación adecuada de las variables del proceso, la aplicación de ultrasonidos redujo el tiempo de extracción de 24 h necesarias en extracción convencional a 15 min, sin modificar la composición de los extractos y su potencial antioxidante.
En cuanto a la estabilidad del extracto, las condiciones de procesado no tuvieron una influencia significativa en la bioaccesibilidad de los extractos. Independientemente del método utilizado, la estabilización de extractos por deshidratación sólo redujo la capacidad antioxidante y el contenido total en compuestos fenólicos en torno a un 10 %. Además, las condiciones de almacenamiento no mostraron ningún efecto significativo (p<0.05) sobre el potencial antioxidante durante los 28 días de almacenamiento.
Combinando secado-impregnación-secado, fue posible desarrollar un producto deshidratado (manzana), estable y rico en compuestos fenólicos naturales (de hojas de olivo o extractos de té). No obstante, cabe destacar que el secado de la manzana fresca jugó un papel más importante en la retención de los polifenoles de hoja de olivo infundidos que el secado final de la manzana impregnada.
En términos generales, las hojas de olivo pueden considerarse como una fuente potencial de compuestos fenólicos naturales. No obstante, el secado y la congelación durante el procesado de la materia prima son factores decisivos para la obtención de extractos naturales con alto potencial antioxidante. Además, la aplicación de ultrasonidos de potencia durante la extracción puede resultar una alternativa no térmica muy interesante de cara a acortar el tiempo de procesado. La estabilidad de los polifenoles de la hoja de olivo, durante el almacenamiento y la digestión in vitro, dependió claramente del compuesto individual considerado. Finalmente, el empleo del extracto de hoja de olivo como medio para enriquecer alimentos sólidos requiere del uso de matrices s / [CA] L'objectiu principal d'aquesta tesi va ser determinar la influència de les principals etapes de processament implicades en l'obtenció d'extractes naturals amb alt potencial antioxidant procedents de subproductes de la indústria de l'oli d'oliva.
En primer lloc, es va estudiar l'efecte de la congelació i/o els mètodes d'assecatge aplicats a fulles d'olivera i pinyolada sobre el contingut fenòlic i la capacitat antioxidant dels extractes.
En segon lloc, es va avaluar, tenint en compte la composició i la cinètica del procés, la intensificació de l'extracció de polifenols de fulla d'olivera amb ultrasons de potència.
En tercer lloc, es va avaluar com les condicions de processament (assecatge i extracció) poden influir en l'estabilitat dels extractes. Així, extractes de fulles d'olivera van ser sotmesos a una digestió in vitro o deshidratats i emmagatzemats a distintes condicions.
Finalment, es va explorar la obtenció d'una matriu vegetal deshidratada (poma) i rica en compostos fenòlics de fulla d'olivera considerant la influència del pretractament de la poma (escaldament i congelació) i de l'assecatge sobre la retenció final dels fenòlics introduïts en la poma.
El potencial antioxidant es va avaluar determinant el contingut fenòlic total i la capacitat antioxidant, així com identificant i quantificant els principals polifenols (HPLC-DAD/MS-MS). A més, en poma l'activitat enzimàtica de la polifenoloxidasa i la peroxidasa i la microestructura.
Els resultats experimentals van destacar que el mètode d'assecatge i el de congelació van influir significativament (p<0,05) en la concentració dels principals polifenols identificats en els extractes. L'assecatge a la temperatura més alta que es va provar va resultar la millor condició de processament per a obtenir extractes amb una alta capacitat antioxidant i un alt contingut fenòlic.
L'aplicació d'ultrasons va ser una manera rellevant i no tèrmica d'accelerar l'extracció d'antioxidants de les fulles d'olivera. Així, amb la combinació adequada de les variables del procés, l'extracció assistida per ultrasons va escurçar el temps d'extracció, de les 24 h requerides en l'extracció convencional a 15 min, sense modificar la composició de l'extracte ni el potencial antioxidant.
Quant a l'estabilitat de l'extracte, les condicions de processament utilitzades per a l'obtenció dels extractes de fulla d'olivera no van tenir una influència significativa en la bioaccessibilitat. Independentment del mètode utilitzat, l'estabilització dels extractes per mitjà de la deshidratació només va reduir la capacitat antioxidant i el contingut fenòlic total al voltant d'un 10 %. A més, les condicions d'emmagatzematge (temperatura i forma de l'extracte: líquid o pols) no van mostrar cap efecte significatiu (p<0,05) en el potencial antioxidant dels extractes durant els 28 dies d'emmagatzematge.
Combinant etapes d'assecatge-impregnació-assecatge fou possible obtenir un producte assecat estable (poma) i ric en compostos fenòlics naturals (de fulles d'olivera o te). No obstant això, cal destacar que l'assecatge de la poma fresca va ser més important i determinant en la retenció dels polifenols de fulla d'olivera que no l'assecatge de la poma impregnada.
En termes generals, les fulles d'olivera es poden considerar com una font potencial de compostos fenòlics naturals. No obstant això, l'aplicació d'assecatge i congelació durant el processament de la matèria primera són factors decisius per a l'obtenció d'extractes naturals amb un alt potencial antioxidant. A més, l'aplicació d'ultrasons de potència durant l'extracció resultà ser una forma no tèrmica de millorar el procés, tot reduint-ne el temps d'extracció. L'estabilitat dels polifenols d'olivera durant l'emmagatzematge i la digestió in vitro va dependre del compost individual considerat. Finalment, la utilització d'extractes de fulla d'olivera per a desenvolupar aliments sòlids enriquits requ / Ahmad-Qasem Mateo, MH. (2015). ASSESSMENT OF THE INFLUENCE OF PROCESSING CONDITIONS ON THE ANTIOXIDANT POTENTIAL OF EXTRACTS OBTAINED FROM OLIVE OIL INDUSTRY BYPRODUCTS [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/53452 / TESIS / Premios Extraordinarios de tesis doctorales / Compendio
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Selección y mejora de ecotipos de pimiento (Capsicum sp.) para agricultura sostenible y calidad nutricional y organolépticaRibes Moya, Ana María 25 January 2021 (has links)
[ES] La actual problemática medioambiental está demandando sistemas de producción más sostenibles, como los de la agricultura ecológica. Una buena alternativa para estos sistemas son las variedades tradicionales de pimiento, con rasgos de calidad característicos y de amplia variabilidad genética, fundamental en los programas de mejora, concretamente para la adaptación a la producción ecológica.
En la presente tesis se ha estudiado la calidad nutricional y organoléptica del cultivo del pimiento (Capsicum sp.) en los dos estados de madurez comercial y bajo diferentes prácticas culturales (sistemas ecológico y convencional). Se han analizado los principales compuestos nutricionales de los frutos de pimiento: el ácido ascórbico, los compuestos fenólicos y los carotenoides; así como la fracción volátil, y se ha estudiado su variación en una amplia colección varietal. Adicionalmente, se ha estudiado la fertilidad biológica del suelo a través de las actividades enzimáticas de la fosfatasa alcalina y la catalasa en interacción con el cultivo del pimiento bajo los sistemas de cultivo convencional y ecológico.
El estudio de la calidad nutricional mostró amplios rangos de variación según el factor genotipo, aunque el estado de maduración y el sistema de cultivo también contribuyeron a las diferencias observadas. En general, los frutos maduros presentaron niveles superiores de compuestos bioactivos, especialmente para el ácido ascórbico. Asimismo, el cultivo ecológico proporcionó, en general, niveles más altos de ácido ascórbico y compuestos fenólicos en estado maduro. La notable interacción genotipo × sistema de cultivo para el contenido en ácido ascórbico y fenoles totales, y en menor intensidad para el contenido en flavonoides individuales, permitió la selección de varias accesiones con alto rendimiento en estos compuestos, bajo condiciones de cultivo ecológico en ambos estados de maduración. Por el contrario, los efectos del sistema de cultivo y la interacción genotipo × sistema de cultivo no resultaron significativos en los niveles de carotenoides, cuya variación se debió principalmente al factor genotipo.
El estudio de la composición volátil permitió encontrar amplias diferencias cuantitativas y cualitativas para este factor de calidad organoléptica en los frutos de pimiento, dependiendo principalmente del factor genético y del estado de maduración, mientras que el sistema de cultivo afectó en menor medida y significativamente a algunos compuestos volátiles individuales. Se encontraron un total de 124 y 122 volátiles en estado inmaduro y maduro, respectivamente. Los cambios en el perfil volátil con la maduración fueron evidentes y muy diversos según el genotipo. En general, el sistema de cultivo ecológico favoreció la acumulación de compuestos volátiles en ambos estados de maduración y durante el proceso de maduración.
Las actividades enzimáticas fosfatasa alcalina y catalasa aumentaron durante la fase de cultivo, con actividades máximas generales en la fase intermedia, especialmente para la fosfatasa alcalina. El sistema de cultivo tuvo una mayor contribución a la variación, resultado significativo y superior para el sistema convencional en fase intermedia para ambas actividades y estando generalmente seguido del factor genotipo, significativo para la fosfatasa alcalina en fase intermedia. La interacción genotipo × sistema de cultivo permitiría seleccionar variedades, con capacidad para que los suelos acumularan mayores valores de las actividades enzimáticas fosfatasa alcalina y catalasa, en el sistema de cultivo ecológico.
En definitiva, los resultados de este trabajo proporcionarán información de especial utilidad para programas de investigación en hortalizas de alto valor añadido y programas de mejora de la calidad en agricultura ecológica, así como para el control de autenticidad de variedades tradicionales. / [CA] L'actual problemàtica mediambiental està demandant sistemes de producció més sostenibles, com els de l'agricultura ecològica. Una bona alternativa per a aquests sistemes són les varietats tradicionals de pebrot, amb trets de qualitat característics i d'àmplia variabilitat genètica, fonamental en els programes de millora, concretament per a l'adaptació a la producció ecològica.
En la present tesi s'ha estudiat la qualitat nutricional i organolèptica del cultiu del pebrot (Capsicum sp.) en els dos estats de maduresa comercial i sota diferents pràctiques culturals (sistemes ecològic i convencional). S'han analitzat els principals compostos nutricionals dels fruits de pebrot: l'àcid ascòrbic, els compostos fenòlics i els carotenoides; així com la fracció volàtil, i s'ha estudiat la seva variació en una àmplia col·lecció varietal. Addicionalment, s'ha estudiat la fertilitat biològica de terra a través de les activitats enzimàtiques de la fosfatasa alcalina i la catalasa en interacció amb el cultiu del pebrot sota els sistemes de cultiu convencional i ecològic.
L'estudi de la qualitat nutricional mostrar amplis rangs de variació segons el factor genotip, encara que l'estat de maduració i el sistema de cultiu també van contribuir a les diferències observades. En general, els fruits madurs van presentar nivells superiors de compostos bioactius, especialment per a l'àcid ascòrbic. Així mateix, el cultiu ecològic va proporcionar, en general, nivells més alts d'àcid ascòrbic i compostos fenòlics en estat madur. La notable interacció genotip × sistema de cultiu per al contingut en àcid ascòrbic i fenols totals, i en menor intensitat per al contingut en flavonoides individuals, va permetre la selecció de diverses accessions amb alt rendiment en aquests compostos, sota condicions de cultiu ecològic en els dos estats de maduració. Per contra, els efectes de el sistema de cultiu i la interacció genotip × sistema de cultiu no van resultar significatius en els nivells de carotenoides, la variació es va deure principalment al factor genotip.
L'estudi de la composició volàtil va permetre trobar àmplies diferències quantitatives i qualitatives per aquest factor de qualitat organolèptica en els fruits de pebrot, depenent principalment del factor genètic i de l'estat de maduració, mentre que el sistema de cultiu va afectar en menor mesura i significativament a alguns compostos volàtils individuals. Es van trobar un total de 124 i 122 volàtils en estat immadur i madur, respectivament. Els canvis en el perfil volàtil amb la maduració van ser evidents i molt diversos segons el genotip. En general, el sistema de cultiu ecològic va afavorir l'acumulació de compostos volàtils en els dos estats de maduració i durant el procés de maduració.
Les activitats enzimàtiques fosfatasa alcalina i catalasa van augmentar durant la fase de cultiu, amb activitats màximes generals en la fase intermèdia, especialment per a la fosfatasa alcalina. El sistema de cultiu va tenir una major contribució a la variació, resultat significatiu i superior per al sistema convencional en fase intermèdia per a ambdues activitats i estant generalment seguit del factor genotip, significatiu per a la fosfatasa alcalina en fase intermèdia. La interacció genotip × sistema de cultiu permetria seleccionar varietats, amb capacitat perquè els sòls acumulessin grans valors de les activitats enzimàtiques fosfatasa alcalina i catalasa, en el sistema de cultiu ecològic.
En definitiva, els resultats d'aquest treball proporcionaran informació d'especial utilitat per a programes d'investigació en hortalisses d'alt valor afegit i programes de millora de la qualitat en agricultura ecològica, així com per al control d'autenticitat de varietats tradicionals. / [EN] The current environmental problem is demanding more sustainable production systems, such as organic farming. A good alternative for these systems are the traditional varieties of pepper, with characteristic quality traits and wide genetic variability, essential in breeding programs, specifically for adaptation to organic production.
In this thesis, the nutritional and organoleptic quality of the pepper crop (Capsicum sp.) at the two ripening stages and under different cultural practices (ecological and conventional systems) has been studied. The main nutritional compounds of pepper fruits have been analysed: ascorbic acid, phenolic compounds and carotenoids; as well as the volatile fraction, and its variation has been studied in a wide varietal collection. Additionally, the biological fertility of the soil has been studied through the enzymatic activities of alkaline phosphatase and catalase in interaction with pepper cultivation under conventional and ecological growing systems.
The study of nutritional quality showed wide ranges of variation according to the genotype factor, although the ripening stage and the growing system also contributed to the differences observed. In general, fully ripe fruits presented higher levels of bioactive compounds, especially for ascorbic acid. Also, organic farming provided, in general, higher levels of ascorbic acid and phenolic compounds at the fully ripe stage. The remarkable genotype × growing system interaction for the content of ascorbic acid and total phenolics, and to a lesser extent for the content of individual flavonoids, allowed the selection of several accessions with high yield in these compounds, under organic farming conditions at both ripening stages. On the contrary, the effects of the growing system and the genotype × growing system interaction were not significant in carotenoid levels, whose variation was mainly due to the genotype factor.
The study of the volatile composition allowed to find wide quantitative and qualitative differences for this organoleptic quality factor in pepper fruits, depending mainly on the genetic factor and the ripening stage, while the growing system affected to a lesser extent and significantly some individual volatile compounds. A total of 124 and 122 volatiles were found at unripe and fully ripe stages, respectively. The changes in the volatile profile with ripening were evident and very diverse depending on the genotype. In general, the organic growing system favoured the accumulation of volatile compounds at both ripening stages and during the ripening process.
Alkaline phosphatase and catalase enzymatic activities increased during the growing phase, with overall peak activities in the intermediate phase, especially for alkaline phosphatase. The growing system had a greater contribution to variation, a significant and superior result for the conventional system in the intermediate phase for both activities and being generally followed by the genotype factor, significant for alkaline phosphatase in the intermediate phase. The genotype × growing system interaction would allow the selection of varieties, with the capacity for soils to accumulate higher values of the enzymatic activities alkaline phosphatase and catalase, in the organic growing system.
In conclusion, the results of this work will provide information of special use for research programs in vegetables with high added value and quality breeding programs in organic farming, as well as for the authenticity control of traditional varieties. / Authors thank seeds providers included in Table 1, like P.W. Bosland, S. Lanteri,
François Jourdan, I. Ruiz de Galarreta and the different Regulatory Boards of the PDOs
and GPIs included in this study. Authors also thank LA UNIÓ for the availability of
experimental fields and the technical support from Manuel Figueroa, Rafael Hurtado,
Antonio Muñoz and Ricard Ballester in the trials. Finally, the advice of Prof. Jaime
Prohens in statistical procedures is also thanked. / Ribes Moya, AM. (2020). Selección y mejora de ecotipos de pimiento (Capsicum sp.) para agricultura sostenible y calidad nutricional y organoléptica [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/159886 / TESIS
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