471 |
Visokovredna funkcionalna jedinjenja iz sporednih proizvoda prerade paradajza / High-valuable functional compounds from tomato by-productsStajčić Slađana 02 November 2012 (has links)
<p>Ekstrakcijom heksanom, a zatim 80% etanolom predhodno pripremljenog tropa od<br />IZ odabranih genotipova Bačka, Knjaz, Novosadski niski, O<sub>2</sub>, Rutgers i Saint Pierre<br />paradajza, dobijeni su heksanski i etanolni ekstrakti tropa. Sadržaj karotenoida u<br />heksanskim i polifenolnih jedinjenja, flavonoida i askorbinske kiseline u etanolnim<br />ekstraktima određen je spektrofotometrijskim metodama. Identifikacija i<br />kvantifikacija pojedinih karotenoida u heksanskim i polifenolnih jedinjenja u<br />etanolnim ekstraktima tropa paradajza izvedena je HPLC analizom. U ostacima<br />nakon ekstrakcija tropa paradajza određen je sadržaj prehrambenih vlakana.<br />Spektrofotometrijskim testovima određena je antiradikalska aktivnost na DPPH<br />radikale i redukciona sposobnost dobijenih ekstrakata. ESR spektroskopijom<br />ispitan je uticaj etanolnih ekstrakata na reaktivne hidroksil i superoksid anjon<br />radikale. Pored toga, ispitana je i helirajuća sposobnost etanolnih ekstrakata.<br />Antiradikalsko delovanje na DPPH radikale ostataka nakon ekstrakcija tropa<br />paradajza radikale, takođe je utvrđeno. Ispitana je in vitro antiproliferativna<br />aktivnost frakcija ekstrakata, njihovim delovanjem na rast tri histološki različite<br />humane ćelijske linije: MCF-7 (adenokarcinom dojke), HeLa (epitelni karcinom<br />cerviksa) i MRC-5 (fetalni fibroblastni karcinom pluća). Rezultati ispitivanja<br />hemijskog sastava, antioksidativne i antiproliferativne aktivnosti ekstrakata, kao i<br />ostataka nakon ekstracija tropa odabranih genotipova paradajza ukazuju na<br />mogućnost iskorišćenja ovog sporednog proizvoda kao potencijalnog izvora<br />prirodnih antioksidanata, koji bi našli primenu u prehrambenoj, farmaceutskoj i<br />kozmetičkoj industriji.</p> / <p>Tomato pomaces obtained from selected tomato genotypes (Bačka, Knjaz, Novosadski niski,<br />O2, Rutgers and Saint Pierre) were extracted sequentially with hexane and 80% ethanol. The<br />content of carotenoids i hexane and total polyphenolics, flavonoids and ascorbic acid in<br />ethanolic extracts was determined by spectrophotometric methods. Identification and<br />quantification of individual carotenoids in hexane and polyphenolics in ethanolic extracts<br />was determined by HPLC analysis. The content of dietary fiber was determined in the<br />residues after extraction of tomato pomaces. The scavenging activity on DPPH radicals and<br />reducing power of the obtained extracts were determined spectrophotometrically. The<br />influence of ethanolic extracts on reactive hydroxyl and superoxide anion radicals was<br />examined by electron spin resonance (ESR) spectroscopy. In addition, the chelating ability of<br />ethanolic extracts was investigated. Scavenging effect on DPPH radicals of the residue after<br />extraction of tomato pomace, has also been established. Antiproliferative activity of<br />investigated extracts was determined in vitro, testing their influence on the growth of three<br />histologically different human cell lines: MCF-7 (breast adenocarcinoma), HeLa (cervix<br />epithelioid carcinoma) and MRC-5 (fetal lung). Based on the results of chemical analysis,<br />significant antioxidant and antiproliferative activity of the tomato waste extracts, as well as<br />residues after extraction showed that tomato waste obtained from different tomato genotypes<br />should be regarded as potential source of natural antioxidants, which can be used for various<br />purposes in the food, pharmaceutical and cosmetic industry.</p>
|
472 |
Stabilita a vlastnosti kombinovaných nápojů a ovocných koncentrátů / Stability and properties of combined beverages and fruit concentratesKlatová, Kamila January 2018 (has links)
This diploma thesis deals with the stability and basic properties of combined beverages and fruit concentrates. The theoretical part describes the production and use of fruit concentrates. Furthermore, the work deals with anthocyanic pigments and phenolic substances. The principle and instrumentation of liquid chromatography and electron paramagnetic resonance were described. In the next subchapter, the methods of determination of total anthocyanins and phenolic substances were described. The experimental part of the thesis described the determination of soluble solids, viscosity and antioxidant activity. The total content of phenolic compounds were determined by the Folin-Ciocalteua method and the total anthocyanins were determined by the pH-differential method. In the samples were determined cyanidine-3-glucoside and cyanidin-3-galactoside by liquid chromatography.
|
473 |
Phytochemical analysis and biological activities of crude extracts from selected Tulbaghia speciesTakaidza, Samkeliso 12 1900 (has links)
PhD (Department of Biotechnology, Faculty of Applied and Computer Sciences), Vaal Universtiy of Technology / The genus Tulbaghia has been used in traditional medicine to treat various ailments such as fever, earache, tuberculosis and esophageal cancer. However, there is limited scientific evidence to support its use. Therefore the objectives of this study were to perform phytochemical analysis, investigate the antioxidant, antimicrobial, anticancer, immunomodulatory activities and toxicity of crude acetone and water extracts from selected Tulbaghia species.
Standard methods were used for preliminary phytochemical analysis. The total phenolic content of the plant extracts was determined using the folin ciocalteu method whereas the total flavonoids were determined by using the aluminium chloride colorimetric method. DPPH and ABTS assays were used to evaluate the antioxidant activity. The antimicrobial activity was assessed by agar well diffusion, microtiter dilution and time kill assays.
For anticancer studies, the antiproliferative activity of the extracts was evaluated using the MTT assay on Hkesc-1 and KB cells. Morphological changes of the cancer cells treated with extracts were examined using light microscopy. Induction of apoptosis was assessed using fluorescence microscopy and acridine orange/ethidium bromide staining. Flow cytometry analysis was conducted to examine the multicaspase activity and cell cycle arrest. For immunomodulatory activity, the Greiss reagent and Luminex cytokine assays were used to determine the effect of the extracts on NO production and the concentration of the cytokines in the treated cells, respectively.
Toxicity of selected Tulbaghia species was examined by investigating the effect of the extracts on the metabolic activity and cell membrane integrity on the treated RAW264.7 cells using the MTT and LDH assays, respectively. The zebrafish assay was used to evaluate the embryotoxicity and teratogenic effects of crude acetone and water extracts of T. violacea at 24 h intervals for 96 h post fertilisation (hpf). The percentage mortality, hatchability and heart rate were examined.
Phytochemical screening of eight Tulbaghia species demonstrated the presence of flavonoids, glycosides, tannins, terpenoids, saponins and steroids. The amount of total phenol and flavonoid content varied in different plant extracts ranging from 4.50 to 11.10 milligrams gallic acid equivalent per gram (mg GAE/g) of fresh material and 3.04 to 9.65 milligrams quercetin equivalent per gram (mg QE/g) of fresh material respectively. The IC50 values based on DPPH and ABTS for T. alliacea (0.06 and 0.06 mg/mL) and T. violacea (0.08 and 0.03 mg/mL) were generally lower showing potential antioxidant activities. For antimicrobial activity, the acetone extracts of T. acutiloba, T. alliacea, T. leucantha, T. ludwigiana, T. natalensis and T. simmleri showed moderate antimicrobial activity against all test organisms while the water extracts showed moderate to no activity. One species, T. cernua, showed poor activity against all the tested microbes. The acetone and water extracts of T. violacea showed the greatest antibacterial and antifungal activity against all the tested microorganisms with minimum inhibitory concentration ranging from 0.1 mg/mL to 3.13 mg/mL. The acetone extracts of T. violacea also exhibited both bacteriostatic/fungistatic and bactericidal/fungicidal activity depending on the incubation time and concentration of the extract. The bactericidal/fungicidal activity was observed at x2 MIC.
The results for anticancer activity showed that treatment of Hkesc-1 cells with acetone and water crude extracts had anti-proliferative activity with IC50 values of 0.4 mg/mL and 1.625 mg/mL, respectively while KB had 0.2 mg/mL and 1 mg/mL, respectively. Morphological changes such as blebbing, cell shrinkage and rounding were observed in the treated cells suggesting that apoptosis was taking place. AOEB staining showed that the level of apoptosis was dependent on the concentration of the extracts. The activation of multicaspase activity in both Hkesc-1 and KB treated cells was also concentration dependent leading to cell death by apoptosis and the induction of cell cycle arrest at the G2/M phase.
Immunomodulatory activity results indicated that cell viability was above 80% when concentrations of 50 µg/mL or less of both acetone and water crude was used. Treatment with the acetone extract had no significant effect (p>0.05) on the LPS induced NO production in RAW264.7 cells except at 50 µg/mL where significant inhibition was observed. The water extract had no significant effect (p>0.05) on NO production at all the concentrations. Treatment of LPS–induced RAW264.7 cells with acetone extract stimulated the production of IL-1α, IL-6 and TNF-α, but had no significant effect (p > 0.05) on IL-1β. On the other hand, treatment with the water extracts stimulated the production of IL-1α, IL-6 but had no significant effect (p>0.05) on TNF-α and IL-1β. Treatment of LPS-induced RAW264.7 cells with the acetone extract had very little stimulatory effect on IL-4, IL-5 and IL-13 and no significant effect on IL-10 whereas for the water extract a significant stimulatory effect was only observed for IL-4 after 48 h of treatment. High concentrations (>10000 pg/mL) of MCP-1, MIP1-α, MIP1-β, MIP-2, GCSF, GM-CSF, RANTES and IP-10 were also observed in acetone and water extract treated RAW264.7 cells.
For toxicity studies, acetone and aqueous crude leaf extracts from T. alliacea, T. simmleri, and T. violacea had a significant inhibitory (p<0.05) effect on the RAW264.7 cells after 48h treatment. Acetone extracts from T. alliacea, T. simmleri and T. violacea resulted in IC50 values of 0.48 mg/mL, 0.72 mg/mL and 0.1 mg/mL, respectively. Treatment with water extracts showed minimal toxic effect indicated by higher IC50 values of 0.95 mg/mL, 2.49 mg/mL and 0.3 mg/mL for T. alliacea, T. simmleri and T. violacea, respectively. The LDH release by macrophages after 24 h treatment with acetone extracts was observed to be concentration dependent while treatment with water extracts did not induce LDH release. The zebra fish assay showed a lethal dose (LD50) for the T. violacea acetone crude extract of 20 μg/mL whereas that for water extract was 85 μg/mL. The observed teratogenic effects included scoliosis, edema of the pericardial cavity, retarded yolk resorption, hook-like/bent tail and shorter body length.
In conclusion, the results from this study indicate that the extracts from the eight Tulbaghia species examined contain phytochemicals that may have the antioxidant, antimicrobial, anticancer and immunomodulatory properties. Extracts from T. violacea were observed to be the most potent. This study thus supports the use of T. violacea in treating bacterial and fungal infections in traditional medicine. The results of this study also confirm the anticancer potential of T. violacea. The immunomodulatory activity of the acetone and water extracts from T. violacea indicated a dominantly pro-inflammatory activity. Traditional medicine prepared form T. violacea may be of benefit to individuals with weak immune systems. The toxicity of selected Tulbaghia species was observed to be concentration, extract and time dependent. Therefore, traditional medicine prepared from Tulbaghia extracts should be taken with caution preferably in small doses over a short period of time. Future studies will focus on the identification of the bioactive compound(s) responsible for the antimicrobial, anticancer and immunomodulatory activities.
|
474 |
The Anti-toxin Properties of Grape Seed Phenolic CompoundsCherubin, Patrick 01 January 2014 (has links)
Corynebacterium diphtheriae, Pseudomonas aeruginosa, Ricinus communis, Shigella dysentariae, and Vibrio cholerae produce AB toxins which share the same basic structural characteristics: a catalytic A subunit attached to a cell-binding B subunit. All AB toxins have cytosolic targets despite an initial extracellular location. AB toxins use different methods to reach the cytosol and have different effects on the target cell. Broad-spectrum inhibitors against these toxins are therefore hard to develop because they use different surface receptors, entry mechanisms, enzyme activities, and cytosolic targets. We have found that grape seed extract provides resistance to five different AB toxins: diphtheria toxin (DT), P. aeruginosa exotoxin A (ETA), ricin, Shiga toxin, and cholera toxin (CT). To identify individual compounds in grape seed extract that are capable of inhibiting the activities of these AB toxins, we screened twenty common phenolic compounds of grape seed extract for anti-toxin properties. Three compounds inhibited DT, four inhibited ETA, one inhibited ricin, and twelve inhibited CT. Additional studies were performed to determine the mechanism of inhibition against CT. Two compounds inhibited CT binding to the cell surface and even stripped bound CT off the plasma membrane of a target cell. Two other compounds inhibited the enzymatic activity of CT. We have thus identified individual toxin inhibitors from grape seed extract and some of their mechanisms of inhibition against CT. This work will help to formulate a defined mixture of phenolic compounds that could potentially be used as a therapeutic against a broad range of AB toxins.
|
475 |
Applications and Effects of Ohmic Heating: Sterilization, Influence on Bacterial Spores, Enzymes, Bioactive Components and Quality Factors in FoodSomavat, Romel 10 January 2011 (has links)
No description available.
|
476 |
Implementación de tecnología de membranas para la valorización de los compuestos fenólicos presentes en las aguas residuales de la industria de producción de aceite de olivaSánchez Arévalo, Carmen María 20 October 2023 (has links)
Tesis por compendio / [ES] El sector agroalimentario constituye una de las industrias con mayor relevancia. Durante la producción de aceite de oliva, se generan grandes volúmenes de subproductos, destacando el alperujo, que contiene todos los restos de la aceituna que permanecen una vez que se ha extraído el aceite. Se trata de un subproducto con una elevada carga orgánica, lo que puede suponer un riesgo ambiental si no se gestiona adecuadamente. Por otro lado, el alperujo es rico en compuestos fenólicos, los cuales tienen un elevado interés industrial, debido a sus propiedades antioxidantes. Esto representa una oportunidad excelente para valorizar el alperujo, recuperando compuestos de interés y reduciendo la carga contaminante del residuo. En esta Tesis Doctoral, se ha abordado este reto, en el marco de la Tecnología de Membranas. En primer lugar, se llevó a cabo la optimización de un proceso de extracción sólido-líquido asistida por ultrasonidos, para extraer los compuestos fenólicos presentes en el alperujo. Se obtuvieron resultados satisfactorios tanto con mezclas de etanol/agua como con agua pura. Además, se llevó a cabo una caracterización detallada de los metabolitos presentes en los extractos derivados del alperujo, de forma que se determinaron más de 50 compuestos. En las siguientes etapas, se emplearon tanto los extractos obtenidos con etanol/agua 50:50 (v/v) como los acuosos. En cuanto a estos últimos, se trataron mediante ultrafiltración, seleccionando las membranas UP005 y UH030, debido a su adecuada productividad y eficacia en términos de rechazo a la demanda química de oxígeno. Los compuestos fenólicos fueron recuperados con mayor pureza en el permeado de este proceso. A continuación, esta corriente de permeado fue sometida a un proceso de nanofiltración, empleando la membrana NF270 (DuPont), para llevar a cabo la concentración de los compuestos fenólicos previamente purificados. Además, se demostró la viabilidad de esta membrana, NF270, para separar compuestos fenólicos de bajo peso molecular y azúcares, empleando disoluciones modelo con una composición basada en las aguas residuales de la industria oleícola. Los extractos hidroalcohólicos de alperujo también fueron tratados mediante procesos de membrana. Previamente, se llevó a cabo una revisión exhaustiva de la literatura científica relacionada con la ultrafiltración en medio orgánico. A continuación, se evaluó un proceso de ultrafiltración para purificar los extractos de alperujo preparados con etanol/agua 50:50 (v/v), obteniendo resultados satisfactorios en cuanto a la estabilidad de las membranas (empleando las membranas UF010104 y UF010801v3, de la casa comercial SolSep BV, y UP005, de Microdyn Nadir) y la recuperación de compuestos fenólicos en el permeado. Para aumentar la pureza de estos compuestos fenólicos y abordar su fraccionamiento, se estudió un proceso de nanofiltración con disolventes orgánicos, empleando una disolución simulada, cuyo disolvente fue etanol/agua 50:50 (v/v), y con una composición basada en el permeado del proceso de ultrafiltración (con la membrana UP005) en medio orgánico. La membrana NF270 fue la más destacada, debido a su notable densidad de flujo de permeado. Además, esta membrana rechazó adecuadamente los compuestos no deseados, como azúcares y ácidos, lo que facilitó la recuperación satisfactoria de los compuestos fenólicos en el permeado. Considerando los resultados obtenidos, se propuso un proceso integrado basado en la extracción de estos compuestos con etanol/agua 50:50 (v/v), la ultrafiltración de este extracto, con la membrana UP005, para llevar a cabo su purificación, la nanofiltración, con la membrana NF270, de la corriente de permeado obtenida previamente, para aumentar la pureza y fraccionar los compuestos fenólicos y, finalmente, la concentración de la corriente de permeado obtenida durante la nanofiltración, mediante un proceso de ósmosis reversa, empleando la membrana NF90 (DuPont) que rechazó apropiadamente los compuestos fenólicos. / [CA] El sector agroalimentari constitueix una de les indústries amb major rellevància. Durant la producció d'oli d'oliva, es generen grans volums de subproductes, entre els quals destaca l'alperujo, que conté totes les restes de l'oliva que romanen una vegada que s'ha extret l'oli. Es tracta d'un subproducte amb una elevada càrrega orgànica, la qual cosa pot suposar un gran risc ambiental. D'altra banda, l'alperujo és ric en compostos fenòlics, els quals tenen un elevat interés industrial, degut a les seues propietats antioxidants. Aquest contingut en compostos bioactius representa una oportunitat excel·lent per a valorar l'alperujo, recuperant compostos d'interés i reduint la càrrega contaminant del residu. En aquesta Tesi Doctoral, s'ha abordat aquest repte, en el marc de la Tecnologia de Membranes. En primer lloc, es va dur a terme l'optimització d'un procés d'extracció sòlid-líquid assistida per ultrasons, per a extraure els compostos fenòlics presents a l'alperujo. Es van obtindre resultats satisfactoris tant amb mescles d'etanol/aigua com amb aigua pura. A més, es va dur a terme una caracterització detallada dels metabòlits presents en els extractes derivats de l'alperujo, de manera que es van determinar més de 50 compostos. En les següents etapes del procés, es van emprar tant els extractes obtinguts amb etanol/aigua 50:50 (v/v) com els extractes aquosos. Quant a aquests últims, es van tractar mitjançant ultrafiltració, estudiant les membranes, seleccionant les membranes UP005 i UH030, a causa de la seua adequada productivitat i eficàcia en termes de rebuig a la demanda química d'oxigen. Els compostos fenòlics van ser recuperats amb major puresa al permeat d'aquest procés. A continuació, el corrent de permeat obtinguda durant l'etapa d'ultrafiltració va ser sotmesa a un procés de nanofiltració, emprant la membrana NF270 (DuPont), per a dur a terme la concentració dels compostos fenòlics prèviament purificats. A més, es va demostrar la viabilitat d'aquesta membrana, NF270, per a separar compostos fenòlics de baix pes molecular i sucres, emprant dissolucions model. Els extractes hidroalcohòlics d'alperujo també van ser tractats mitjançant processos de membrana. Prèviament, es va dur a terme una revisió exhaustiva de la literatura científica relacionada amb la ultrafiltració al mig orgànic. A continuació, es va avaluar un procés d'ultrafiltració per a purificar els extractes d'alperujo preparats amb etanol/aigua 50:50 (v/v), obtenint resultats satisfactoris quant a l'estabilitat de les membranes (emprant les membranes UF010104 i UF010801v3, de la casa comercial SolSep BV, i UP005, de Microdyn Nadir) i la recuperació de compostos fenòlics, els quals es van obtindre en el corrent de permeat. Per augmentar la puresa d'aquests compostos fenòlics i abordar el seu fraccionament, es va estudiar un procés de nanofiltració amb dissolvents orgànics, utilitzant una dissolució simulada, que el seu dissolvent va ser etanol/aigua 50:50 (v/v), i amb una composició basada en el permeat del procés d'ultrafiltració al mig orgànic. D'entre totes les membranes, la membrana NF270 va ser la més destacada, a causa de la seua notable densitat de flux de permeat. A més, aquesta membrana va rebutjar adequadament els compostos no desitjats, com a sucres i àcids, la qual va facilitar la recuperació satisfactòria dels compostos fenòlics en el permeat. Considerant els resultats obtinguts, es va proposar un procés integrat basat en l'extracció d'aquests compostos amb etanol/aigua 50:50 (v/v), la ultrafiltració d'aquest extracte, amb la membrana UP005, per a dur a terme la seua purificació, la nanofiltració, amb la membrana NF270, del corrent de permeat obtinguda prèviament, per augmentar la puresa i fraccionar els compostos fenòlics i, finalment, la concentració del corrent de permeat obtinguda durant la nanofiltració, mitjançant un procés d'osmosi reversa, emprant la membrana NF90 (DuPont) que va rebutjar apropiadament els compostos fenòlics. / [EN] The agri-food sector is one of the industries with higher international relevance. During olive oil production, large volumes of by-products are generated. Among them, the wet olive pomace stands out. It contains all the olive components remaining after the olive oil extraction. This by-product has a high organic load, which may represent an environmental risk if it is not properly disposed. On the other side, the wet olive pomace is rich in phenolic compounds, which have high industrial interest due to their antioxidant properties. This content in bioactive compounds represents an excellent opportunity to valorize the wet olive pomace, recovering compounds of interest and reducing the contaminant load of the residue. In this Doctoral Thesis, this challenge has been addressed, in the framework of Membrane Technology. First, an ultrasound-assisted solid-liquid extraction was optimized to extract the phenolic compounds from wet olive pomace. Satisfactory results were obtained, both with mixtures of ethanol/water and with pure water. Furthermore, a detailed characterization of the metabolites present in the extracts derived from wet olive pomace was conducted. More than 50 compounds were determined. During the following stages, both the extracts obtained with ethanol/water 50:50 (v/v) and the aqueous extracts were considered. The aqueous extracts were treated by ultrafiltration, selecting the UP005 and UH030 membranes, due to their suitable productivity and efficacy, in terms of the rejection of the chemical oxygen demand. The phenolic compounds were recovered at a higher purity in the permeate. Afterwards, the ultrafiltration permeate was treated by nanofiltration, employing the NF270 membrane (DuPont), in order to concentrate the previously purified phenolic compounds. Moreover, the feasibility of the NF270 membrane to separate low-molecular-weight phenolic compounds from sugars was demonstrated. To that end, simulated solutions, with a composition based on olive mill wastewaters, were employed. The hydroalcoholic extracts of wet olive pomace were also treated by membrane processes. Previously, an exhaustive review of the scientific literature related to organic-solvent ultrafiltration was addressed. Later, it was evaluated an ultrafiltration process to purify the wet olive pomace extracts prepared with ethanol/water 50:50 (v/v). Satisfactory results were obtained, regarding the membranes stability (UF010104 and UF010801v3, from the manufacturer SolSep BV, and UP005, from Microdyn Nadir) and the recovery of phenolic compounds. These molecules were obtained in the permeate stream. To increase the purity of the phenolic compounds and address their fractionation, an organic-solvent nanofiltration process was studied. A simulated solution, whose solvent was ethanol/water 50:50 (v/v), was employed. The composition of this solution was based on the UP005 permeate obtained in organic media. Among all the evaluated membranes, the NF270 membrane stood out due to the high permeate flux. Furthermore, this membrane properly rejected the unwanted compounds, such as sugars and acids. This allowed the satisfactory recovery of phenolic compounds in the permeate stream, after their purification and fractionation. Considering these results, an integrated process was proposed. It was based on the extraction of the compounds of interest with ethanol/water 50:50 (v/v), and a further ultrafiltration, nanofiltration, and reverse osmosis process. The ultrafiltration of the extract was performed with the UP005 membrane to conduct its purification. Then, the UP005 permeate was nanofiltered, employing the NF270 membrane to enhance the purity of the phenolic compounds and fractionate them. Finally, the NF270 permeate was concentrated by means of a reverse osmosis process, employing the NF90 membrane (DuPont), which suitably rejected the phenolic compounds. / Sánchez Arévalo, CM. (2023). Implementación de tecnología de membranas para la valorización de los compuestos fenólicos presentes en las aguas residuales de la industria de producción de aceite de oliva [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/198859 / Compendio
|
477 |
Etude des composés phénoliques impliqués dans la réponse des feuilles de vigne au mildiou / Study of phenolic compounds involved in the response of grapevine leaves to downy mildewBellow, Sébastien 06 June 2012 (has links)
Maîtriser l’impact des maladies sur les cultures est un défi majeur de l’agriculture moderne. Cette préoccupation est un aspect important de l’optimisation de la productivité, notamment en viticulture. En France, le mildiou de la vigne causé par Plasmopara viticola est une des maladies cryptogamiques responsable des épidémies les plus dévastatrices et les plus redoutées. Les traitements reposent sur l’utilisation préventive, systématique et onéreuse de composés chimiques antifongiques dont l’utilisation massive constitue un risque à la fois pour l’homme et l’environnement. La réduction de l’utilisation de fongicide implique le développement d’outils de diagnostic au champ, qui requiert la compréhension des interactions entre la plante et les agents pathogènes. Les travaux de cette thèse pluridisciplinaire ont porté sur le pathosystème Plasmopara viticola - Vitis vinifera, notamment pour répondre à l’intérêt croissant pour un outil de diagnostic en temps réel de la maladie utilisable au vignoble. Les stilbènes sont des phytoalexines impliqués dans la défense de certaines plantes supérieures vis-à-vis de stress biotiques et abiotiques. L’autofluorescence de ces composés phénoliques, dont la biosynthèse est induite dans les feuilles de vigne par P. viticola, en fait un potentiel marqueur naturel de l’infection. En effet, la faible autofluorescence bleu-verte des feuilles de vigne saines est considérablement renforcée par l’autofluorescence violet-bleue des stilbènes à la surface de feuilles de vigne infectée par P. viticola. Cette étude a montré que quelque soit le niveau de résistance du génotype, l’autofluorescence violet-bleue des stilbènes induit par l’infection est présente au niveau des parois des cellules de l’épiderme. En dehors de la concentration, la viscosité s’est révélé être la principale variable physico-chimique influençant l’intensité de l’autofluorescence des stilbènes dans les différents compartiments cellulaires des feuilles de vigne. Ceci explique la fluorescence intense des parois, particulièrement rigides, des cellules de garde (stomates) des feuilles infectées. Le suivi cinétique journalier a révélé la nature transitoire de l’autofluorescence des stilbènes lors de l’infection. La robustesse et l’intérêt de ce signal a également été validée par la mesure à différentes échelles (de la cellule à la feuille entière) et avec différentes méthodes fluorimétriques. Les résultats de ce travail ont permis des avancées sur la connaissance du rôle de composés phénoliques induits et constitutifs dans la défense contre P. viticola. En plus de la localisation de l’autofluorescence des stilbènes en surface des feuilles, la microscopie confocale couplée à la microspectrofluorimetrie a révélé différentes localisations de ces phytoalexines dans la profondeur des tissus en corrélation avec le niveau de résistance des génotypes. L’utilisation de l’autofluorescence des stilbènes comme marqueur de l’infection a permis de mettre en évidence : 1) le fait que les flavonols constitutifs des feuilles de V. vinifera retardent le développement de l’infection par P. viticola; et 2) le fait que les acides hydroxycinnamiques constitutifs ne semble pas participer à la défense contre P. viticola. Enfin, une nouvelle méthode de diagnostic non-destructive du mildiou sur feuille basée sur l’autofluorescence des stilbènes a été développée. Elle a montré une détection pré-symptomatique du mildiou sur les feuilles de vigne entières dès le premier jour après l’infection sur la face abaxiale et le troisième jour sur la face adaxiale. Cette méthode de diagnostic du mildiou a été validée au laboratoire notamment grâce à un prototype de capteur proximal développé en collaboration avec la société Force-A. La validation de la méthode au vignoble dans le cadre d’infection naturelle est la prochaine étape pour une utilisation de ce capteur optique dans le cadre de l’agriculture durable et de la sélection variétale. / Controlling the impact of diseases on crops is a major challenge of modern agriculture. This concern is an important aspect of optimizing productivity, notably in viticulture. In France, downy mildew caused by Plasmopara viticola is a fungal disease responsible for the most devastating epidemics. The preventive and systematic treatments are expensive, while the massive use of antifungal chemicals is a risk to both humans and the environment. Reducing the use of fungicide involves the development of diagnostic tools in the field, which requires understanding the interactions between plants and pathogens. The work of this multidisciplinary thesis focused on the pathosystem Plasmopara viticola - Vitis vinifera, especially to meet the growing interest in a real-time diagnostic tool of disease applicable in the vineyard. Stilbenes are phytoalexins involved in the defense of certain higher plants against biotic and abiotic stresses. The autofluorescence of these phenolic compounds, whose biosynthesis is induced in grapevine leaves by P. viticola, makes it a potential marker of natural infection. Indeed, the low blue-green autofluorescence of grapevine leaves is greatly enhanced by the violet-blue autofluorescence of stilbenes on the surface of leaves infected by P. viticola. This study showed that whatever the level of resistance in various genotypes, violet-blue autofluorescence induced by stilbene is present in the walls of epidermal cells. In addition to their concentration, viscosity proved the main physico-chemical variable affecting the intensity of the autofluorescence of stilbenes in different compartments of vine leaves. This explains the intense fluorescence of the walls, particularly rigid, of guard cells (stomata) of infected leaves. Daily monitoring revealed a kinetic with a transient rise of the autofluorescence of stilbenes during infection. The robustness and value of this signal was also validated by measuring at different levels (cellular to whole leaf) and with various fluorimetric methods (imaging, spectroscopy, proximal sensing). These results advance our understanding of the role of constitutive and induced phenolic compounds in plant defence against P. viticola. In addition to a common location of the autofluorescence of stilbenes on the leaf surface, confocal microscopy coupled with microspectrofluorometry revealed distinctive localizations of these phytoalexins in the deep tissue correlated with the level of resistance in genotypes. This aspect no doubt needs broader testing. The use of autofluorescence of stilbene as a marker of infection allowed us to ascertain that: 1) constitutive flavonols of the leaves of V. vinifera retard the development of infection by P. viticola and 2) the constitutive hydroxycinnamic acids do not seem to participate in the defence against P. viticola. Finally, a new method for the non-destructive diagnosis of leaf infection based on the autofluorescence of stilbenes has been developed. We have demonstrated a pre-symptomatic detection of downy mildew on whole grape leaves from the first day after infection on the abaxial surface and from the third day on the adaxial surface. This method of diagnosis has been validated in the laboratory thanks to a proximal sensor prototype developed in collaboration with the company Force-A. The validation of the method in the vineyard in a context of natural infections is the next step for use of this optical sensor as a tool for sustainable agriculture and for genetic screening.
|
478 |
Efeito dos compostos fenólicos presentes no alecrim (Rosmarinus officinalis L.) sobre as enzimas antioxidantes e os parâmetros bioquímicos do sangue de ratos diabéticos induzidos por estreptozotocina (OU) Efeito dos compostos fenólicos presentes no alecrim (Rosmarinus officinalis L.) sobre as enzimas antioxidantes e os parâmetros bioquímicos de ratos diabéticos induzidos por estreptozotocina / Effect of the phenolic compounds present in rosemary (Rosmarinus officinalis L.) on the antioxidant enzymes and the biochemical parameters of diabetic rats induced by streptozotocinSilva, Ana Mara de Oliveira e 30 May 2008 (has links)
As ervas e especiarias são fontes de antioxidantes. Essa capacidade antioxidante está relacionada aos compostos fenólicos que apresentam papel importante nos processos de inibição da peroxidação e podem atuar sobre o estresse oxidativo, relacionado com diversas patologias, inclusive o diabetes. O alecrim é bastante apreciado por seu aroma e sabor, tendo como constituintes os seguintes compostos fenólicos: ácido carnósico, carnosol, ácido rosmarínico, ácido caféico e éster do ácido hidroxicinâmico. Objetivou-se avaliar a capacidade antioxidante in vitro de extratos e frações de ácidos fenólicos obtidos das folhas de alecrim e seu efeito sobre ratos diabéticos induzidos por estreptozotocina. Constatou-se que tanto os extratos como as frações apresentaram altos teores de compostos fenólicos totais e expressiva atividade antioxidante in vitro nos três métodos utilizados: β-caroteno/ácido linoléico, varredura do radical DPPH e ORAC. No ensaio in vivo, foi utilizado modelo de diabetes tipo 1, apresentando as características principais: poliúria, polifagia, polidipsia e perda de peso. Observaram-se alterações na atividade das enzimas antioxidantes, nos parâmetros bioquímicos do sangue e aumento significativo (p<0,05) da glicemia, no percentual de hemoglobina glicosilada (Hb-G), nos níveis de triglicérides, de colesterol total, de creatinina, de AL T e de AST. O extrato aquoso de alecrim administrado por 30 dias na concentração de 50 mg/Kg aumentou a atividade das enzimas CAT e GPx, no fígado, e da SOD no cérebro de ratos diabéticos, diminuindo também o percentual de Hb-G. A mesma dose, quando administrada por 60 dias, reduziu o percentual de Hb-G, nos lipídios circulantes, na creatinina, na atividade das enzimas SOD e GPx dos tecidos avaliados e manteve os valores normais das enzimas de função hepática AL T e AST. Não foi observado efeito dose resposta nos parâmetros analisados, sugerindo que a maior dose (100mg/Kg) apresentou níveis de toxicidade que devem ser melhor caracterizados. Portanto, o extrato aquoso de alecrim apresentou capacidade antioxidante in vitro significativa e quando administrado na concentração de 50 mg/Kg pode ter papel importante sobre o estresse oxidativo presente no diabetes experimental. / Herbs and spices are potential sources of antioxidants. This antioxidant capacity is related to the presence of phenolic compounds that play an important role in the peroxidation inhibition processes, that can act on the oxidative stress, which is related to various diseases, including the diabetes. Rosemary is much appreciated due to its aroma and flavor properties, and has the following constituents as phenolic compounds: carnosic acid, carnosol, rosmannlc acid, cafeic acid, and hydroxycinnamic ester. This study aimed to evaluate the in vitro antioxidant capacity of the extracts and fractions of phenolic acids obtained from the leaves of rosemary and its effect on diabetic rats induced by streptozotocin. The results showed that both extract and fractions contains high leveis of total phenolic compounds, and a significant in vitro antioxidative activity evaluated by three methods: β-carotene / Linoleic acid system, DPPH radical scavenging and ORAC. For in vivo tests, it was used a type 1 diabetes model, which presented the main clinicai features: polyuria, polyfagia, polydipsia, and weight loss. It was also observed the following changes in biochemical markers: an altered antioxidant enzymatic activity; a significant increase (p<0.05) of blood glucose, percentage of glycosylated hemoglobin (Hb-G), triglycerides, total cholesterol, creatinine, and enzymes ALT and AST. The aqueous extract of rosemary administered daily for 30 days at dose of 50 mg/kg increased the activity of enzymes CAT and GPx in the liver and SOD in the brain of diabetic rats, also decreased the percentage of Hb-G. The same dose, when administered for 60 days, led to a reduction of percentage of Hb-G, circulating lipids, and creatinine, also reducing the activity of enzymes SOD and GPx in the analyzed tissues, and maintaining the normal function of liver enzymes AL T and AST. There was no dose¬response effect on the studied parameters. Some toxic effect was observed when higher doses were used (100 mg/kg) but this effect must be better characterized. Therefore, aqueous extracts of rosemary at dose of 50 mg/kg presented a significant in vitro antioxidant capacity that can be an important role on the oxidative stress in experimental diabetes.
|
479 |
CONTRIBUIÇÃO AO CONHECIMENTO QUÍMICO DOS METABÓLITOS SECUNDÁRIOS DE TRÊS ESPÉCIES BACCHARIS DA SEÇÃO CYLINDRICAE: Baccharis pentodonta, Baccharis tridentata e Baccharis rufescensSimioni, Raquel Endler 29 August 2013 (has links)
Made available in DSpace on 2017-07-24T19:38:10Z (GMT). No. of bitstreams: 1
Raquel Simioni.pdf: 2107045 bytes, checksum: 0dadb3940e17669ea7a07463fcfe1389 (MD5)
Previous issue date: 2013-08-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This research aimed to chemically study the secondary metabolites from inflorescences and leaves of male and female specimens of three species from the genus Baccharis: B. rufescens, B. pentodonta and B. tridentata. The plant materials were hydrodistilled for the collection and analysis of the obtained essential oils by GC/MS/FID, UV-Vis, IR and 1H and 13C NMR. The column chromatographic fractionation of the essential oil from male specimens of B. rufescens led to the isolation of two sesquiterpene alcohols, namely spathulenol and (E)-nerolidol, and the ketone 4,7(11)-amorphadien-8-one, which was obtained for the first time making it possible to study its structure using 2D NMR techniques. The essential oils of female specimens of B. rufescens were analyzed by 13C NMR, confirming the presence of (E)-nerolidol and the absence of the mentioned ketone. The oils of male and female specimens of B. pentodonta were very similar, presenting the major sesquiterpenes spathulenol, epiglobulol, viridiflorol, (+)-torreyol and α-cadinol. Likewise, the compositions of the essential oils from male and female specimens of B. tridentata were very similar, showing spathulenol as the major component, followed by caryophyllene oxide and (+)-torreyol. The aqueous extract remaining after the steam distillation of essential oils from B. tridentata was subjected to extraction with chloroform and then with ethyl acetate at pH 8 and pH 4. The extract obtained with ethyl acetate at pH 8 was analyzed by UV-Vis and shift reagents were added, making it possible to observe the presence of a flavanone whose 1H and 13C NMR spectra indicate that this substance is eriodictyol. The extract was chromatographed on a column of silica and structure of eriodictyol was carried out by UV-Vis, IR and 1H and 13C NMR. The ethyl acetate extract at pH 4 was analyzed by UV-Vis and 1H and 13C NMR, verifying the likely presence of 3-caffeoylquinic acid, 3,5-dicaffeoylquinic acid and 4,5-dicaffeoylquinic acid. / O presente estudo teve como objetivo estudar quimicamente os metabólitos secundários de inflorescências e folhas de espécimes masculinos e femininos de três espécies do gênero Baccharis: B. rufescens, B. pentodonta e B. tridentata. Os materiais vegetais foram hidrodestilados para a obtenção e análise dos óleos essenciais por técnicas de CG-EM-DIC, UV-Vis, IV e RMN de 1H e de 13C. O fracionamento em coluna cromatográfica do óleo essencial de espécimes masculinos de B. rufescens levou ao isolamento de dois álcoois sesquiterpênicos, espatulenol e (E)-nerolidol, e da cetona 4,7(11)-amorfadien-8-ona, que foi obtida pela primeira vez em quantidade suficiente para estudos detalhados sobre sua estrutura com uso de técnicas de RMN 2D. Os óleos essenciais de espécimes femininos de B. rufescens foram analisados por RMN de 13C, confirmando a presença majoritária de (E)-nerolidol e ausência da mencionada cetona. Os óleos de espécimes masculinos e femininos de B. pentodonta mostraram-se muito similares entre si, identificando-se como majoritários os sesquiterpenos espatulenol, epiglobulol, viridiflorol, (+)-torreiol e α-cadinol. Da mesma forma, as composições dos óleos essenciais de espécimes masculinos e femininos de B. tridentata mostraram-se muito similares, identificando-se o espatulenol como componente majoritário, seguido de óxido de cariofileno e (+)-torreiol. O extrato aquoso restante após a hidrodestilação dos óleos essenciais de B. tridentata foi submetido à extração com clorofórmio e em seguida com acetato de etila em pH 8 e em pH 4. O extrato obtido com acetato de etila em pH 8 foi analisado por UV-Vis com adição de reagentes de deslocamento, tornando possível observar a presença de uma flavanona cujos espectros de RMN de 1H e de 13C indicaram tratar-se de eriodictiol. O extrato foi cromatografado em coluna de sílica e a estrutura do eriodictiol foi assegurada por UV-Vis, IV e RMN de 1H e de 13C. O extrato acetato de etila em pH 4 foi analisado por UV-Vis e RMN de 1H e de 13C, verificando-se a provável presença do ácido 3-cafeoilquínico, ácido 3,5-dicafeoilquínico e ácido 4,5-dicafeoilquínico.
|
480 |
Uticaj kvaliteta semenki grožđa na bioaktivne komponente i održivost hladno presovanog ulja / Impact of grape seed quality on bioactive components and stability of cold pressed oilBjelica Miloš 27 September 2019 (has links)
<p>Podizanje novih zasada i povećanje kapaciteta prerade<br />grožđa povećava količinu otpada sa kojim se suočava<br />industrija proizvodnje vina i rakije. Najbolji i najodgovorniji<br />način upravljanja otpadom je njegovo dalje iskorišćenje<br />kao nusproizvoda. U ovoj disertaciji sagledavana je mogućnost iskorišćenja<br />nusproizvoda iz različitih faza proizvodnje u vinarijama i<br />destilerijama za dobijanje semenki grožđa koje su<br />korišćene za proizvodnju hladno presovanog ulja. Hipoteza<br />se zasniva na činjenici da semenke grožđa raznih sorti iz<br />različitih faza proizvodnje vina (bela, roze ili crvena vina),<br />odnosno, rakije mogu imati sasvim različit hemijski sastav i<br />kvalitet koji svakako može da se reflektuje na kvalitet,<br />bioaktivne komponente i održivost hladno presovanog ulja.<br />Ovakav proizvod, obzirom da je dobijen hladnim<br />presovanjem, može biti veoma atraktivan za potrošače,<br />zbog svojih specifičnih senzorskih i nutritivnih<br />karakteristika.<br />Za potrebe izrade disertacije prikupljeni su nusproizvodi<br />i pripremljeni su uzorci iz vinarija i destilerija fruškogorskog<br />vinogorja. Dobijene su semenke i proizvedeno hladno<br />presovano ulje od semenki crnog grožđa sorte Merlot,<br />belog grožđa sorte Italijanski rizling i belog grožđa sorte<br />Sila, kao autohtone sorte vinove loze. Hladno presovana<br />ulja su proizvedena od semenki grožđa koje nisu prošle<br />nikakav tretman, odnosno dobijene su nakon presovanja,<br />prilikom proizvodnje belih (Italijanski rizling i Sila) i roze<br />(Merlot) vina, zatim od semenki koje su prošle proces<br />fermentacije prilikom proizvodnje crvenih vina (Merlot) i od<br />semenki koje su prošle proces fermentacije i destilacije<br />prilikom proizvodnje rakije (Merlot, Italijanski rizling i Sila).<br />Pored navedenih semenki i ulja, pripremljen je i prosečan<br />proizvodni uzorak koji predstavlja uzorak dobijen od svih<br />prikupljenih semenki. Kao uporedni uzorci korišćeno je<br />nerafinisano i rafinisano ulje od semenki grožđa nabavljeno<br />na tržištu. Za realizaciju postavljenog cilja, rad na izvođenju ove<br />disertacije obuhvatio je različite faze. U prvoj fazi<br />prikupljene su semenke grožđa i ispitivane su njihove<br />tehničko-tehnološke karakteristika i kvalitet. Zatim su od<br />navedenih semenki proizvedena hladno presovana ulja.<br />U sledećim fazama, ovako dobijena uja, zajedno sa<br />uzorkom nerafinisanog i rafinisanog ulja od semenki<br />grožđa sa tržišta ispitivana su sa aspekta senzorskog i<br />nutritivnog kvaliteta i praćene su razlike u održivosti ulja.<br />Izvršena je senzorska analiza, određivane su frakcije<br />pigmenata, karotenoidi i hlorofili, merena je transparencija,<br />a parametri boje ulja određivani su i instrumentalno.<br />Nutritivni kvalitet ulja sagledavan je na osnovu sadržaja i<br />sastava bioaktivnih komponenti, pre svega tokoferola i<br />tokotrienola, fenola i sterola. Budući da ova jedinjenja<br />ispoljavaju značajne antioksidativne aktivnosti izvršeno je i<br />ispitivanje antiradikalske aktivnosti uzoraka. Odživost ulja<br />od semenki grožđa sagledana je na osnovu početnog<br />kvaliteta i oksidativnog stanja, kao i rezultata ubrzanih<br />testova, kao što je Rancimat test, Schaal-oven test i<br />fluorescentni test.<br />Na osnovu dobijenih rezultata, može se konstatovati da<br />su svi dobijeni uzorci semenki imali dobru skladišnu vlagu,<br />koja, obzirom na mali sadržaj ulja u semenkama, može da<br />osigura čuvanje semenki u dužem periodu. Sadržaj ulja u<br />semenkama, pored uticaja sorte vinove loze, zavisi i od<br />uticaja procesa kome su podvrgnute semenke pre<br />presovanja (fermentacija, destilacija).<br />Senzorska analiza ulja od semenki grožđa pokazala je<br />značajne razlike u karakteristikama koje su posledica ne<br />samo načina dobijanja ulja (hladno presovano ili rafinisano), sorte vinove loze, već i postupka dobijanja,<br />porekla i kvaliteta semenki grožđa. Uslovi kojima su<br />semenke grožđa izložene u toku alkoholne fermentacije i<br />posebno destilacije utiču na formiranje specifične arome<br />hladno presovanog ulja. I pored toga što se pojavljuje<br />izuzetno širok spektar različitih aroma, mirisa i ukusa u ulju<br />i što postoje značajne razlike u aromi ulja u zavisnosti od<br />sorte grožđa, moguće je prepoznati da li je hladno<br />presovano ulje dobijeno od semenki grožđa bez<br />fermentacije, posle fermentacije ili posle destilacije.<br />Takođe, sa aspekta boje ulja može se kazati da rafinisano<br />ulje od semenki grožđa ima svetlo žutu boju sa<br />zelenkastom nijansom, dok su hladno presovana ulja<br />intenzivnijih boja i kreću se od žuto-zelenkaste, preko<br />zelenkasto žute i svetlo zelenkaste do tamno zelene. Veći<br />udeo zelene boje imaju hladno presovana ulja od semenki<br />grožđa dobijenih posle destilacije.<br />U radu je pokazano da sadržaj pigmenata (karotenoida i<br />hlorofila) u velikoj meri zavisi od porekla semenki.<br />Postupak fermentacije doprinosi povećanju sadržaja<br />pigmenata, dok postupak destilacije, zbog visokih<br />temperatura ima negativan efekat.<br />Transparencija uzoraka hladno presovanih ulja od<br />semenki grožđa proizvedenih za potrebe disertacije kretala<br />se od 32,8% do 53,8%.<br />Sadržaj nezasićenih masnih kiselina u svim uzorcima<br />ulja od semenki grožđa veći je od 90%, pri čemu<br />dominantnu masnu kiselinu čini linolna, omega-6, masna<br />kiselina.<br />Sadržaj tokotrienola je veći od sadržaja tokoferola u uljima od semenki grožđa, a dominantni tokoferol je alfatokoferol.<br />Njegov sadržaj je veći u uzorcima ulja dobijenim<br />iz semenki nakon fermentacije i destilacije.<br />Sadržaj fenolnih jedinjenja, u zavisnosti od sorte, u<br />proseku je nešto viši u hladno presovanim uljima dobijenim<br />od crvene sorte grožđa, ali uočava se i značajan porast<br />(akumulacija) fenola u hladno presovanim uljima dobijenim<br />iz semenki grožđa nakon procesa fermentacije i destilacije.<br />Najveći pojedinačni sadržaju u ulju od semenki grožđa ima<br />ursolna kiselina, a pored nje značajniji sadržaj, mada<br />mnogo manji, pokazuju rezveratrol, kemferol i vanilinska<br />kiselina.<br />Najzastupljeniji steroli ulja semenki grožđa su β-<br />sitosterol sa udelom od 62,59-69,74%, stigmasterol sa<br />udelom od 12,13-15,00% i kampesterol sa udelom od 6,59-<br />11,94% u ukupnim sterolima. Na sadržaj fitosterola u<br />uljima od semenki grožđa nemaju uticaja procesi<br />fermentacije i destilacije kojima su podvrgnute semenke<br />pre preosvanja.<br />U radu je dokazan negativan uticaj procesa fermentacije<br />i destilacije kojima su povrgnute semenke grožđa na<br />antiradikalski potencijal dobijenih ulja. Antiradikalski<br />potencijal ulja od semenki grožđa zavisi i od sorte vinove<br />loze, kao i od načina dobijanja ulja (hladno presovano ili<br />rafinisano).<br />Procesi fermentacije i destilacije utiču i na osnovni<br />hemijski kvalitet dobijenih hladno presovanih ulja na način<br />da dovode do povećanja kiselinskog i peroksidnog broja.<br />Hladno presovana ulja od semenki grožđa pokazuju<br />dobru oksidativnu stabilnost. Rancimat test je pokazao razlike u indukcionom periodu hladno presovanih ulja od<br />semenki grožđa kao posledicu razlike u sorti, kao i u<br />načinu dobijanja semenki. Proces fermentacije utiče na<br />povećanje, a proces destilacije na smanjenje indukcionog<br />perioda.<br />Na osnovu svih dobijenih rezultata istraživanja može se<br />konstatovati da su hladno presovana ulja od semenki<br />grožđa pokazala različit nutritivni kvalitet i oksidativnu<br />stabilnost, zbog specifičnih razlika koje su posledica razlika<br />u sorti i poreklu semenki, tj. zbog specifičnog efekta<br />fermentacije i destilacije na semenke od kojih je ulje<br />proizvedeno, čime je i potvrđena hipoteza.</p> / <p>Raising new plantations and increasing the grape<br />processing capacity increases the amount of waste faced<br />by the wine and brandy industry. The best and most<br />responsible way of waste management is its further<br />exploitation as by-products.<br />In this dissertation, the possibility of using by-products from different stages of production in wineries and distilleries for<br />obtaining grape seeds, which were used for the production<br />of cold pressed oil, was examined. The hypothesis is<br />based on the fact that grape seeds of various varieties<br />from different stages of wine production (white, rose or red<br />wine), that is, brandy can have a completely different<br />chemical composition and quality that can certainly be<br />reflected on the quality, bioactive components and stability<br />of cold pressed oil.<br />Such a product, as it is obtained by cold pressing, can<br />be very attractive to consumers, due to its specific sensory<br />and nutritional characteristics.<br />For the needs of the dissertation, the by-products were<br />collected and samples were prepared from the wineries<br />and distilleries of the Fruška Gora vineyard. Seeds were<br />obtained and cold pressed oil produced from Merlot grape<br />seed, as representatives of red grape varieties, Italian<br />Riesling, as representatives of white grape varieties and<br />Sila, as new white grape varieties. Cold pressed oils were<br />produced from grape seeds that did not undergo any<br />treatment, that is, they were obtained after pressing, during<br />the production of white (Italian Riesling and Sila) and rose<br />(Merlot) wines, then from the seeds that were fermented<br />during the production of red wines (Merlot ) and seeds that<br />have undergone fermentation and distillation process<br />during the production of brandy (Merlot, Italian Riesling and<br />Sila). In addition to the mentioned seeds and oils, an<br />average production sample was prepared, which is a<br />sample obtained from all collected seeds. Unrefined and<br />refined grape seed oil purchased on the market was used<br />as comparative samples. For realization of the set goal, the work on the<br />performance of this dissertation encompassed different<br />phases. In the first phase, grape seed were collected and<br />their technical and technological characteristics and quality<br />were examined. Then cold-pressed oils were produced<br />from these seeds.<br />In the following phases, the resulting ear, together with a<br />sample of unrefined and refined grape seed oil from the<br />market, were examined from the aspect of sensory and<br />nutritional quality and differences in oil stability were<br />observed. Sensory analysis was performed, pigmentate<br />fractions, carotenoids and chlorophylls were determined,<br />transparency was measured, and oil color parameters<br />were also determined instrumentally. The nutritive oil<br />quality was examined based on the content and<br />composition of bioactive components, primarily tocopherols<br />and tocotrienols, phenols and sterols. Since these<br />compounds exhibit significant antioxidant activities, the<br />antiradical activity of the samples was also tested. The<br />stability of grape seed oils was examined based on the<br />initial quality and the oxidative state, as well as the results<br />of accelerated tests, such as Rancimat test, Schaal-oven<br />and fluorescence test.<br />On the basis of the obtained results, it can be concluded<br />that all the obtained seed samples had good storage<br />moisture, which, given the small content of oil in the seeds,<br />can ensure the storage of seeds for a longer period. The<br />content of oil in the seed, in addition to the influence of the<br />grape variety, depends on the influence of the process to<br />which the seeds are subjected to pressing (fermentation,<br />distillation). Sensory analysis grape seed oils showed significant<br />differences in characteristics that are due not only to the<br />method of obtaining oil (cold pressed or refined), grape<br />varieties, but also the method of obtaining, the origin and<br />quality of grape seed. The conditions for grape seeds<br />exposed during fermentation and especially distillation<br />affect the formation of a specific cold pressed oil. Although<br />an extremely wide range of different flavors, odors and<br />flavors in oil appear, and there are significant differences in<br />the aroma of the oil, depending on the grape variety, it is<br />possible to recognize whether the cold-pressed oil is<br />derived from the grape seed without fermentation, after<br />fermentation or after distillation. Also, from the aspect of oil<br />color it can be said that refined grape seed oil has a light<br />yellow color with a greenish shade, while cold pressed<br />grape seed oils have more intense colors range from<br />yellowish-greenish, over greenish yellow and light greenish<br />to dark green. A higher proportion of green color has cold<br />pressed grape seed oils obtained after distillation.<br />The thesis has shown that the content of pigments<br />(carotenoids and chlorophyll) depends to a great extent on<br />the origin of the seed. The fermentation process<br />contributes to increasing the content of pigments, while the<br />distillation process has a negative effect due to high<br />temperatures.<br />Transparency of cold pressed grape seed oils produced<br />for the dissertation ranged from 32.8% to 53.8%.<br />The content of unsaturated fatty acids in all samples of<br />grape seed oil is greater than 90%, with the dominant fatty<br />acid being linoleic, omega-6, fatty acid. The content of tocotrienols is higher than the content of<br />tocopherols in grape seed oils, and the dominant<br />tocopherol is alpha-tocopherol. Its content is higher in oil<br />samples obtained from the seed after fermentation and<br />distillation.<br />The content of phenol compounds, depending on the<br />variety, is somewhat higher in cold pressed oils obtained<br />from red grape varieties, but there is also a significant<br />increase in accumulation of phenol in cold pressed oils<br />obtained from the grape seed after the fermentation and<br />distillation process. The largest individual oil content of<br />grape seeds has ursolic acid, and besides it, significant<br />content, although much smaller, shows rezveratrol,<br />kemferol and vanillinic acid.<br />The most prevalent sterols of grape seed oils are β-<br />sitosterol with a share of 62.59-69.74%, stigmasterol with a<br />share of 12.13-15.00% and campesterol with a share of<br />6.59-11.94% in total sterols. Fermentation and distilation<br />processes, to which the seeds have been exposed, have<br />no effect on the content of phytosterols in grape seed oils.<br />The paper has shown the negative influence of the<br />fermentation and distillation process, to which the seeds<br />have been exposed, onto the antiradical potential of the<br />obtained oils. The antiradical potential of grape seed oils<br />depends on grape varietes, as well as on the way oil is<br />obtained (cold pressed or refined).<br />Processes of fermentation and distillation also affect the<br />basic chemical quality of obtained cold pressed oils in such<br />a way as to increase the acid and peroxide values.<br />Cold pressed grape seed oils show good oxidative stability. The Rancimat test showed differences in the<br />induction period of cold pressed grape seed oils as a result<br />of the variation in the variety, as well as in the method of<br />obtaining the seed. The fermentation process affects the<br />increase, and the process of distillation decreases the<br />induction period.<br />Based on all the obtained results, it can be concluded<br />that cold pressed grape seed oils showed different<br />nutritional quality and oxidative stability due to specific<br />differences resulting from differences in variety and seed<br />origin, i.e. due to the specific effect of fermentation and<br />distillation processes on the seeds from which the oil was<br />produced, thus confirming the hypothesis.</p>
|
Page generated in 0.0534 seconds