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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Characterization of A-type Proanthocyanidins in Peanut Skins Using MALDI-TOF MS

Ye, LiYun 27 February 2015 (has links)
Peanut skin, a low-value agriculture waste product, has drawn lots of research interest in recent years, due to its high content of A-type proanthocyanidins. A-type proanthocyanidins have been believed to contribute to cranberries' anti-UTI (urinary tract infection) effect. In this study, we compared the A-type proanthocyanidins in cranberry and peanut skin crude extracts using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Many similarities were found in the proanthocyanidin composition of cranberries and peanut skins. New oligomeric and polymeric proanthocyanidins in peanut skins, including heteroproanthocyanidins and proanthocyanidins with sugar moieties or galloyl esters, were tentatively identified. Solid phase extraction (SPE) and HPLC fractionation largely improved MALDI-TOF's ability to detect proanthocyanidins with high degrees of polymerization (DP). By analyzing the identified compounds in each fraction, we were also able to find some interesting elution pattern of the proanthocyanidins on the SPE cartridges and on the HPLC column. For example, the elution order on both the SPE cartridges and the diol phase column generally followed the DP. A-type proanthocyanidins tended to elute earlier than the B-type. Prodelphinidins retained much longer than other proanthocyanidins with the same DP. These findings may help researcher to identify future research directions and develop new separation methods to facilitate the identification of bioactive components in proanthocyanidin-rich plant extracts. / Ph. D.
2

Identification of Phenolic Compounds from Peanut Skin using HPLC-MSn

Reed, Kyle Andrew 07 January 2010 (has links)
Consumers view natural antioxidants as a safe means to reduce spoilage in foods. In addition, these compounds have been reported to be responsible for human health benefits. Identification of these compounds in peanut skins may enhance consumer interest, improve sales, and increase the value of peanuts. This study evaluated analytical methods which have not been previously incorporated for the analysis of peanut skins. Toyopearl size-exclusion chromatography (SEC) was used for separating phenolic size-classes in raw methanolic extract from skins of Gregory peanuts. This allowed for an enhanced analysis of phenolic content and antioxidant activity based on compound classes, and provided a viable preparatory separation technique for further identification. Toyopearl SEC of raw methanolic peanut skin extract produced nine fractions based on molecular size. Analysis of total phenolics in these fractions indicated Gregory peanut skins contain high concentrations of phenolic compounds. Further studies revealed the fractions contained compounds which exhibited antioxidant activities that were significantly higher than that of butylated hydroxyanisole (BHA), a common synthetic antioxidant used in the food industry. This indicates peanut skin extracts are a viable antioxidant source, and that synthetic antioxidants can be replaced with those naturally-derived from peanut by-products. Structures contained in each fraction were identified using high performance liquid chromatography (HPLC) coupled with electrospray ionization (ESI) ion trap mass spectrometry (MSn). Prior to this study, approximately 20 compounds have been identified in peanut skins. The combination of Toyopearl SEC with ESI-HPLC-MSn allowed for the identification of 314 phenolic-based compounds, most of which are newly discovered compounds in peanut skins. Many compounds identified are known to have powerful antioxidant effects, and also have been reported to exhibit numerous beneficial chemical and biological activities, including the treatment of various human health-related conditions. It is evident that peanut skins may be a potential untapped source for the extraction of natural food antioxidants, nutracueticals, and even pharmaceuticals. Because peanut skins are largely a wasted resource to peanut processors, the novel polyphenols identified in this research could have a significant financial impact on the peanut industry. / Ph. D.
3

Flavonoid biosynthesis in bilberry (<em>Vaccinium myrtillus</em> L.)

Jaakola, L. (Laura) 21 November 2003 (has links)
Abstract Flavonoids are a class of secondary metabolites in plants that are involved in many important functions. Various flavonoid compounds have also been reported to be beneficial for human health. Bilberry (Vaccinium myrtillus L.) is the characteristic field layer species in boreal forests and the fruits of bilberry are rich in anthocyanin pigments, a subclass of flavonoids. In the present work, flavonoid biosynthesis was examined in different tissues of bilberry. The focus was on the developing fruits of wild type and natural color mutants of bilberry, and on effect of solar radiation on flavonoid biosynthesis in bilberry leaves. For the isolation of RNA for gene expression analysis, a method was optimized for different tissues of bilberry. The cDNA fragments of five genes from the flavonoid pathway, coding phenylalanine ammonia-lyase, chalcone synthase, flavanone 3-hydroxylase, dihydroflavanol 4-reductase and anthocyanidin synthase, were isolated from bilberry using polymerase chain reaction technique, sequenced, and labelled with dioxigenin-dUTP label. These homologous, bilberry-specific probes were used for determining the expression of the flavonoid pathway genes in bilberry fruits, flowers and leaves with a modified non-radioactive method developed in the course of the study. The anthocyanins, catechins, proanthocyanidins, flavonols and hydroxycinnamic acids in fruits, leaves and different fractions of bilberry were identified and quantified with high-performance liquid chromatography combined with a diode array detector and mass spectrometer. The results demonstrate a correlation between anthocyanin accumulation and expression of the flavonoid pathway genes during the ripening of berries. A correlation between flavonol and anthocyanin biosynthesis was detected in bilberry and also in previous literature collected from flavonol and anthocyanin analyses from other fruits. Accordingly, models for the connection between flavonol and anthocyanin synthesis in fruit species were suggested. Activation of the expression of flavonoid pathway genes and accumulation of flavonoids and hydroxycinnamic acids was detected in leaves growing under direct solar radiation, compared to the shadow leaves of the same plants. Based on the results, it is suggested that cyanidin of anthocyanins and flavonol quercetin play a predominant role in the defence against high solar radiation in Vaccinium leaves. The results give new information about the biosynthesis of flavonoids in bilberry at the gene level, in addition to the information of the composition and content of flavonoids during fruit development and in different parts of the bilberry plant. Also, new information was obtained of the roles of flavonoids in protecting plants from excess solar radiation.
4

Lesão renal aguda por glicerol: efeito antioxidante da Vitis Vinifera L. / Acute kidney injury by glycerol: antioxidant effect of Vitis Vinifera L.

Martim, Elisabete Cristina de Oliveira 06 August 2007 (has links)
A Lesão Renal Aguda (LRA) é a complicação mais grave da rabdomiólise. Nessa síndrome, a liberação do pigmento heme desencadeia uma lesão que se caracteriza por vasoconstrição glomerular e toxicidade celular direta com componente oxidativo. A lesão oxidativa desencadeada é uma das linhas fisiopatológicas mais intrigantes. A renoproteção com antioxidantes tem demonstrado efeito satisfatório. As proantocianidinas são antioxidantes naturais encontrados no extrato da semente da uva. O objetivo deste estudo foi avaliar o efeito antioxidante da Vitis vinifera (extrato da semente de uva) sobre a função renal de ratos submetidos à lesão por rabdomiólise. Foram utilizados ratos Wistar, adultos machos, pesando entre 250-300 gramas. A LRA foi induzida pela administração de glicerol 50% i.m (intramuscular). Os animais foram distribuídos em 4 grupos: grupo Salina (6ml/Kg de NaCl 0,9% via intraperitoneal (i.p) 1 vez ao dia), grupo Glicerol (6ml/Kg de glicerol i.m, cada região femoral recebeu 3ml/Kg de glicerol, 1 vez ao dia), grupo Vitis vinifera (3mg/Kg v.o por 5 dias) e grupo Glicerol+Vitis vinifera que recebeu Vitis vinifera por 5 dias antes do glicerol. Foram avaliados o marcador de lesão muscular (CK), a função renal (FR), a função tubular (FENa e FEK), o perfil oxidativo (peróxidos urinários-FOX-2 e MDA-TBARS) , a histologia e morfometria renal. O grupo Glicerol tratado com Vitis vinifera apresentou melhora da FR e tubular, redução dos níveis da peroxidação lipídica e melhora da histologia renal. Os resultados deste estudo confirmaram a proteção antioxidante, com repercussão histológica, da Vitis vinifera na LRA induzida por glicerol. / The Acute Kidney Injury (AKI) is the worst complication of rhabdomyolysis. In this syndrome, the delivery of heme pigment induces an injury that distinguishes itself by glomerular vasoconstriction and direct cellular toxicity with oxidative component. The oxidative injury is an intriguing one of the pathophysiological mechanism. The renoprotection with antioxidants has demonstrated satisfactory effect. The proanthocyanidins are natural antioxidants found in grape seed extract. The aim of this study was to evaluate the antioxidant effect of Vitis vinifera (grape seed extract) on the renal function of rats submitted to the injury by rhabdomyolysis. Wistar rats, male, adults, weight ranging from 250-300 g were used. The AKI was induced intramuscular (i.m.) administration of glycerol 50%. The animals were distributed in 4 groups: Saline group (6ml/Kg of NaCl 0,9% intraperitoneal (i.p) once a day), Glycerol group (6ml/Kg of glycerol i.m, each femoral region received 3ml/Kg of glycerol, once a day), Vitis vinifera group (3mg/Kg v.o by 5 days) and Glycerol+Vitis vinifera group that has received Vitis vinifera by 5 days before glycerol. Marker of muscular injury (CK), renal function (RF), the tubular function (FENa and FEK), the oxidative profile (urinary peroxides -FOX-2 and MDA-TBARS), the histological and kidney morphometric were evaluated. The Glycerol group treated with Vitis vinifera has shown improvements in RF and tubular, reduction of levels of lipid peroxidation and amelioration of kidney histology. The results of this study have confirmed the antioxidant protection, with histological repercussion of Vitis vinifera in AKI induced by glycerol.
5

Compostos fenólicos, capacidade antioxidante e alcaloides em folhas e frutos (pericarpo, polpa e sementes) de Passifloras spp / Phenolic compounds, antioxidant capacity and alkaloids in leaves and fruit (pericarp, pulp and seeds) of Passifloras spp.

Vieira, Gabriella Pedrosa 10 March 2014 (has links)
A cultura popular atribui ao gênero Passiflora várias propriedades medicinais e funcionais. Frutas frescas e secas, cascas, infusões e suco da polpa de maracujás silvestres são consumidos e comercializados para controlar ansiedade, insônia, tremores, diabetes e obesidade, entre outras indicações. Dessa forma, os objetivos deste trabalho foram caracterizar e comparar as folhas e frutos (pericarpo, polpa e sementes) das espécies P. edulis Sims variedades BRS Sol do Cerrado, Ouro Vermelho e Gigante Amarelo, P. alata Curtis, P. setacea DC e P. tenuifila Killip em relação ao seu potencial funcional, avaliando-se conteúdos de compostos fenólicos totais, proantocianidinas, vitamina C, alcaloides, tipos e teores de flavonoides, controle potencial de glicemia pós-prandial (inibição de &#945;-amilase e &#945;-glicosidase in vitro) e capacidade antioxidante in vitro. O principal flavonoide encontrado tanto em folhas como em frutos foi a homoorientina e as maiores concentrações foram encontradas em folhas, seguido de pericarpo. Os maiores teores de alcaloides foram detectados nas polpas dos frutos de P. edulis (0,1-0,2 mg/100 g b.s.). As maiores concentrações de compostos fenólicos foram detectadas nas folhas de P. edulis e P. alata, porém as sementes de P. tenuifila e principalmente P. setacea apresentaram os teores mais elevados em comparação com as outras frações. Em relação às proantocianidinas, este é o primeiro estudo que mostra a presenças destes compostos em Passiflora spp, em concentrações significativamente maiores nas sementes. Além disso, o estilbeno piceatanol (3,4,3\',5\'-tetrahidroxi-trans-estilbeno) também foi encontrado nas sementes de P. edulis variedades BRS Ouro Vermelho (2 mg/100 g b.s.) e Gigante Amarelo (3 mg/100 g b.s.) e P. alata (10 mg/100 g b.s.). Os compostos fenólicos encontrados nas sementes de todas as espécies de Passiflora analisadas se mostraram potentes inibidores das enzimas &#945;-amilase e &#945;-glicosidase. Este trabalho mostrou que os frutos e as folhas de Passiflora spp podem ser considerados boas fontes de compostos bioativos, especialmente com atividade antioxidante, apresentando, portanto, potenciais efeitos benéficos sobre a saúde humana. / Folk culture assigns to the genus Passiflora various medicinal and functional properties. Fresh and dried fruits , barks , teas and wild passion fruit pulp juice are consumed and sold to control anxiety, insomnia , tremor , diabetes and obesity , among other indications .Thus, the aim of this study were to characterize the leaves and fruit (pericarp , pulp and seeds) of the species P. edulis Sims varieties BRS Sol do Cerrado, Ouro Vermelho e Gigante Amarelo, P. alata Curtis, P. setacea DC e P. tenuifila Killip in relation to their functional potential , evaluating content of total phenolic compounds , proanthocyanidins , vitamin C , alkaloids , types and levels of flavonoids, potential control of postprandial glycemia (inhibition of &#945;-amylase and &#945;-glucosidase in vitro) and in vitro antioxidant capacity. The main flavonoid found in both leaves and fruits was homoorientina and the highest concentrations were found in leaves, followed by pericarp . The highest levels of alkaloids were detected in the pulp of the fruits of P. edulis ( 0.1-0.2 mg/100 g b.s. ) . The highest concentrations of phenolic compounds were identified in the leaves of P. edulis and P. alata, but the seeds of P. tenuifila and especially P. setacea showed higher levels compared with the other fractions . With respect to proanthocyanidin, this is the first study to show the presence of these compounds in Passiflora spp at concentrations significantly increased in seeds. Furthermore, piceatannol stilbene ( 3,4,3\',5\'- tetrahydroxy -trans- stilbene ) was also found in the seeds of P. edulis varieties BRS Ouro Vermelho (2 mg/100 g d.w.) and Gigante Amarelo (3 mg/100 g d.w.) and P. alata (10 mg/100 g d.w.). Phenolic compounds found in the seeds of all species analyzed are good inhibitors of &#945;-amylase and &#945;-glicosidase. This work showed that the fruit and leaves of Passiflora spp. can be considered good sources of bioactive compounds, especially with antioxidant activity, thus presenting potential beneficial effects on human health.
6

Investigating the effects of cranberry juice on the physicochemical properties of Escherichia coli for the prevention of urinary tract infections

Pinzon-Arango, Paola A. 09 January 2008 (has links)
The adhesion of bacteria to uroepithelial cells or urinary catheters is the first step in the development of biofilm formation and urinary tract infections (UTIs). Previous research has suggested that consumption of cranberry juice can prevent the recurrence of UTIs by decreasing bacterial adhesion since isolated compounds in cranberries, known as A-type proanthocyanidins (PACs), change the conformation of proteinaceous fimbriae that help attach bacteria to epithelial cell receptors. Most clinical and laboratory studies have shown the effects of cranberry juice cocktail (CJC) on large communities of bacteria; however, very few studies have evaluated how cranberry affects the adhesion forces of a single bacterium as well as effects on cellular composition and biofilm formation. We used atomic force microscopy (AFM) to investigate the effects of CJC and PACs on the adhesion forces between E. coli and a silicon nitride tip. Bacterial cultures were grown in tryptic soy broth (TSB), supplemented with 0 and 10 wt.% light cranberry juice cocktail (L-CJC) or 128 µg/mL PACs. E. coli bacteria were continuously cultured in the presence of cranberry products up to twelve times. Experiments were conducted at different scales to test bacterial attachment and adhesion forces. At the macroscale, bacteria were incubated with uroepithelial cells and the number of bacteria attached per uroepithelial cell was determined. In nanoscale experiments, the forces of adhesion between E. coli and a silicon nitride AFM tip were probed for bacteria grown in L-CJC or PACs for different numbers of culture times. Successive replacement of media and continued culture in L-CJC and PACs resulted in a significant decrease in adhesion forces for E. coli strains. Finally, during the continuous exposure of L-CJC to bacteria we examined the growth, morphology, and ability to form biofilms of E. coli. We found a decrease in growth rates related to changes in Gram staining with increasing number of cultures in L-CJC. Growth of bacteria in L-CJC or PACs inhibited the development of biofilms on polyvinyl-chloride, which can model biofilm formation on urinary catheters. We also determined that growth of E. coli in L-CJC results in prevention of the expression of indole which can be linked to the inhibition of biofilm formation. Our results help support the molecular mechanisms for the role of cranberry in preventing the adhesion of E. coli to biotic and abiotic surfaces, thus helping to scientifically validate the use of cranberry juice as a prophylactic treatment for the prevention of UTIs.
7

Lesão renal aguda por glicerol: efeito antioxidante da Vitis Vinifera L. / Acute kidney injury by glycerol: antioxidant effect of Vitis Vinifera L.

Elisabete Cristina de Oliveira Martim 06 August 2007 (has links)
A Lesão Renal Aguda (LRA) é a complicação mais grave da rabdomiólise. Nessa síndrome, a liberação do pigmento heme desencadeia uma lesão que se caracteriza por vasoconstrição glomerular e toxicidade celular direta com componente oxidativo. A lesão oxidativa desencadeada é uma das linhas fisiopatológicas mais intrigantes. A renoproteção com antioxidantes tem demonstrado efeito satisfatório. As proantocianidinas são antioxidantes naturais encontrados no extrato da semente da uva. O objetivo deste estudo foi avaliar o efeito antioxidante da Vitis vinifera (extrato da semente de uva) sobre a função renal de ratos submetidos à lesão por rabdomiólise. Foram utilizados ratos Wistar, adultos machos, pesando entre 250-300 gramas. A LRA foi induzida pela administração de glicerol 50% i.m (intramuscular). Os animais foram distribuídos em 4 grupos: grupo Salina (6ml/Kg de NaCl 0,9% via intraperitoneal (i.p) 1 vez ao dia), grupo Glicerol (6ml/Kg de glicerol i.m, cada região femoral recebeu 3ml/Kg de glicerol, 1 vez ao dia), grupo Vitis vinifera (3mg/Kg v.o por 5 dias) e grupo Glicerol+Vitis vinifera que recebeu Vitis vinifera por 5 dias antes do glicerol. Foram avaliados o marcador de lesão muscular (CK), a função renal (FR), a função tubular (FENa e FEK), o perfil oxidativo (peróxidos urinários-FOX-2 e MDA-TBARS) , a histologia e morfometria renal. O grupo Glicerol tratado com Vitis vinifera apresentou melhora da FR e tubular, redução dos níveis da peroxidação lipídica e melhora da histologia renal. Os resultados deste estudo confirmaram a proteção antioxidante, com repercussão histológica, da Vitis vinifera na LRA induzida por glicerol. / The Acute Kidney Injury (AKI) is the worst complication of rhabdomyolysis. In this syndrome, the delivery of heme pigment induces an injury that distinguishes itself by glomerular vasoconstriction and direct cellular toxicity with oxidative component. The oxidative injury is an intriguing one of the pathophysiological mechanism. The renoprotection with antioxidants has demonstrated satisfactory effect. The proanthocyanidins are natural antioxidants found in grape seed extract. The aim of this study was to evaluate the antioxidant effect of Vitis vinifera (grape seed extract) on the renal function of rats submitted to the injury by rhabdomyolysis. Wistar rats, male, adults, weight ranging from 250-300 g were used. The AKI was induced intramuscular (i.m.) administration of glycerol 50%. The animals were distributed in 4 groups: Saline group (6ml/Kg of NaCl 0,9% intraperitoneal (i.p) once a day), Glycerol group (6ml/Kg of glycerol i.m, each femoral region received 3ml/Kg of glycerol, once a day), Vitis vinifera group (3mg/Kg v.o by 5 days) and Glycerol+Vitis vinifera group that has received Vitis vinifera by 5 days before glycerol. Marker of muscular injury (CK), renal function (RF), the tubular function (FENa and FEK), the oxidative profile (urinary peroxides -FOX-2 and MDA-TBARS), the histological and kidney morphometric were evaluated. The Glycerol group treated with Vitis vinifera has shown improvements in RF and tubular, reduction of levels of lipid peroxidation and amelioration of kidney histology. The results of this study have confirmed the antioxidant protection, with histological repercussion of Vitis vinifera in AKI induced by glycerol.
8

Influência de quimioterápicos e citocinas inflamatórias na síntese de metaloproteinases por fibroblastos e sua modulação por derivados de proantocianidinas e laserterapia de baixa intensidade /

Cardoso, Lais Medeiros. January 2019 (has links)
Orientador: Fernanda Gonçalves Basso / Resumo: A mucosite é um dos principais efeitos adversos do tratamento oncológico e apresenta influência significativa na morbidade e qualidade de vida dos pacientes submetidos a este tipo de tratamento. A etiopatogenia desta condição vem sendo relacionada não só a toxicidade direta dos quimioterápicos e radiação ionizante, mas também a uma ativação exacerbada da resposta inflamatória dos tecidos. Recentemente, o desenvolvimento e a severidade da mucosite oral também tem sido relacionada a expressão exacerbada de metaloproteinases (MMPs), que resulta na desorganização dos tecidos epitelial e conjuntivo e consequentemente, em atraso do processo de reparo. O manejo da mucosite oral tem sido baseado na utilização de agentes analgésicos tópicos, antibióticos e antifúngicos, bem como na aplicação da laserterapia de baixa intensidade (LBI). A LBI apresenta resultados positivos sobre as lesões de mucosite oral, porém, esta modalidade terapêutica requer a utilização de um equipamento de custo moderado e deve ser feita sob supervisão. Desta forma, novas estratégias preventivas e terapêuticas, que possam atuar na modulação da resposta inflamatória e na expressão de MMPs para diminuir a incidência e a severidade das lesões de mucosite oral e também acelerar o processo de reparo têm sido propostas. Estudos recentes demonstraram a efetividade de compostos naturais, como as antocianinas, na redução da incidência e severidade destas lesões. O objetivo desta pesquisa in vitro foi avaliar comparativam... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Mucositis is the major adverse effect of oncological treatment and presents huge impact on oncological patients' morbidity and quality of life. Etiopathogenesis of oral mucositis has been not only related to a direct toxicity of chemotherapy drugs and radiant therapy, but also to an extended inflammatory reaction. Recently, development and severity of oral mucositis has also been associated to increased expression of metalloproteinases (MMPs), that results in disorganization of epithelial and connective tissues, leading to a delayed tissue healing. Treatment of oral mucositis is based on the application of topic analgesic and antimicrobial compounds, as also low-level lasertherapy (LLLT). LLLT shows positive outcomes on oral mucositis, however, this therapy requires the use of a moderate cost equipament and professional supervision. Therefore, new preventive and therapeutic strategies that can act on the modulation of inflammatory response as well as on MMPs expression could decrease the incidence and severity of oral mucositis, therefore enhancing oral mucosa healing. Recent studies demonstrated the effectiveness of natural compounds, such as antocyanins on the decreased incidence and severity of these lesions. Consequently, the aim of the present in vitro study were to assess the effects of proanthocyanidins (PAs, grape seed extract), naringenin (NA, proanthocyanidins-derived synthetic compound), also denominated flavanones, and LLLT as modulators for synthesis of interleukin-6 and MMPs from gingival fibroblasts. Cells were isolated from the papillary gingival tissue of a young (24 years) and healthy individual by enzymatic digestion, then cultured and submitted to different treatments. The influence of two chemotherapeutic agents (5-fluorouracil - 5-FU and methotrexate - MTX) and inflammatory cytokines (TNF-α, IL-6 and -8) on the induction of MMP-2 and -9 synthesis and gene expression were ... (Complete abstract electronic access below) / Mestre
9

The Role Cranberry Proanthocyanidins Play in the Primary Attachment of Bacteria to Surfaces: Bacillus cereus Model

Jones, Anthony Robert 30 November 2008 (has links)
The development of a proanthocyanidin (PAC) treatment, along with the understanding of its mechanism of action, would provide an alternative method of preventing attachment to and colonization of surfaces by microorganisms, as well as potentially disrupting preexisting biofilms. The purpose of this research is to examine the role a cranberry proanthocyanidin plays in the primary attachment of Bacillus cereus to an abiotic surface. This technology could be employed in food processing plants where a premium is placed on maintaining a sanitized work environment to prevent product contamination. A biofilm assay showed that a surface treated with proanthocyanidins actually promoted rather than prevented the attachment of Bacillus cereus. This was further made evident by the fact that the surface hydrophobicities of B. cereus cells grown in media supplemented with proanthocyanidins were greater than those grown in its absence. In addition, light microscopy analysis showed a greater degree of sporulation of B. cereus cells when grown on TSA plates supplemented with PACs. These results suggest that proanthocyanidins may be inducing endospore formation in Bacillus cereus leading to increased attachment and surface hydrophobicity values.
10

Proantocianidinas de uvas y vinos de las variedades Monastrell,Cabernet Sauvignon y Syrah.

Busse Valverde, Naiara 20 March 2013 (has links)
En esta Tesis doctoral se han estudiado las proantocianidinas de pieles y semillas de uvas de las variedades Monastrell, Cabernet Sauvignon y Syrah, así como la transferencia de las mismas al vino y el efecto de algunas técnicas enológicas en la modulación de su extracción. Los resultados obtenidos muestran que la concentración de estos compuestos es máxima al inicio de la maduración, disminuyendo conforme se acerca el momento de la vendimia. La cantidad de proantocianidinas en los vinos depende tanto de la variedad como de la técnica enológica aplicada. Tiempos de maceración largos y técnicas como la maceración prefermentativa en frío o el uso de enzimas de maceración promueven una mayor extracción de proantocianidinas, aunque las de las uvas de la variedad Syrah son mucho más fácilmente extraíbles que las de Monastrell, en igualdad de condiciones. / In this thesis, skin and seed proanthocyanidins of Monastrell, Cabernet Sauvignon and Syrah grape varieties have been studied, as well as their transfer from grapes to wine and the effect of some oenological techniques in modulating their extraction. The results show that the concentration of these compounds was maximum at the beginning of ripening, decreasing up to moment of harvest. The concentration of proanthocyanidins in wines depends both on the variety and the applied oenological technique. Long maceration times and techniques such as cold soak or the use of maceration enzymes promote a large extraction of proanthocyanidins, although, under similar conditions, the proanthocyanidins of Syrah grapes are more easily transferred to must/wine than those of Monastrell grapes.

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