The perception of wine’s quality is directly influenced by its color. Anthocyanin molecules are responsible for imparting color to red wines. They are extracted from grape skins during alcoholic fermentation. This work compares the effects of three parameters: berry integrity, enzyme addition, and fermentation temperature, on phenolic compound extraction (total phenol, tannin and anthocyanin) during the production of Paso Robles’ Cabernet Sauvignon wine. Analyses on phenolic compounds were completed during alcoholic fermentation and barrel aging over the course of eighteen months. Berry integrity compared the degree of berry crushing (whole destemmed berries versus fully crushed berries). Results showed that phenolic compound content after alcoholic fermentation seem to be unaffected by this parameter, while minor increases in total phenol concentration (3%) and tannin concentration (3%) during barrel aging were observed. Adding pectinase-rich macerating enzymes increased the total phenols by 8.7 and 21.0% to the 2010 and 2011 vintage, respectively, and tannin concentrations by 20.8 and 48.8%, respectively, during barrel aging. Alcoholic fermentation temperature of 25.0°C was compared to a fermentation temperature of 32.2°C in the 2011 vintage. When fermented at 32.2°C, concentrations of total phenol and tannin were significantly increased (20.6% and 28.9%, for the 2010 and 2011 vintages, respectively) when compared to 25.0°C. A cooler fermentation temperature led to 57.5% greater anthocyanin concentration throughout barrel aging. The results suggested that fermenting berries at a cooler temperature (25.0°C) increased anthocyanin levels and decreased total phenol and tannin concentration, which are desired outcomes for Paso Robles’ Cabernet Sauvignon wine quality.

Staphylococcus aureus is one of the major causes of food-borne pathogenesis. Antibiotic consumption for these pathogens has been increasing year by year world-wide. In order to decrease the use of synthetic antibiotics, fresh fruits and dry herbs consumed as beverages in regular diets were examined as potential natural antibiotics for the treatment of food based infections against Staphylococcus aureus. Herbs consumed as tea infusions including Pimpinella anisum L. (anise), Anthemis arvensis L. (camomile), Rosa canina L. (rosehip), Salvia fruticosa Mill (sage) and fresh fruit juices including Vitis vinifera L. (grape), Citrus sinensis L. (orange), Prunus persica L. (peach) and Punica granatum L. (pomegranate) were selected as samples of hot or cold consumed beverages in our daily diets. Extracts of fresh fruit juices were prepared in methanol, on the other hand, tea infusions of herbs were filtered and lyophilized. Antioxidant capacities of the plant samples were investigated by radical scavenging methods, namely 2&rsquo / 2-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) as well as determination of total phenolic and flavonoid contents. Furthermore, antimicrobial activities of plant samples were determined by minimum inhibitory concentration and minimum bactericidal concentration methods along with disc diffusion method. Trolox equivalent antioxidant capacities (TEAC) of the herbal tea infusions obtained by ABTS radical scavenging method were ranged between 48.38 &plusmn / 1.242 and 715.73 &plusmn / 4.265 (&mu / mol Trolox equivalent (TE)/g of extract) while, TEAC values of fresh fruits juices were between 26.86 &plusmn / 0.217 and 73.55 &plusmn / 0.973 (&mu / mol Trolox equivalent (TE)/g of extract). Moreover, EC50 values of the tea infusions obtained by DPPH radical scavenging method were ranged between 0.05 &plusmn / 0.001 and 1.53 &plusmn / 0.004 (mg/mL) while, EC50 values of the fruit juices were 1.6 &plusmn / 0.014 and 2 &plusmn / 0.093 (mg/mL). Total phenolic content of the plant samples tested in this study were varied from 1.383 (&mu / g gallic acid equivalent (GAE)/mg of extract) to 159.167 (&mu / g gallic acid equivalent (GAE)/mg of extract) and total flavonoid content varied from 0.111 (&mu / g quercetin equivalent (QE)/mg of extract) to 201.15 (&mu / g quercetin equivalent (QE)/mg of extract). Sage, orange and grape displayed higher antimicrobial activities with values of 1.5, 6 and 6 mg/mL minimum inhibitory concentrations and 1.5, 24 and 24 mg/mL minimum bactericidal concentrations, respectively. Inhibition zone diameters of sage, orange and grape were found to be 9, 9 and 11 mm.

Ce travail avait pour objectif l'étude de l'impact des deux procédés : la déshydratation imprégnation par immersion (DII) et le séchage convectif menés séparément ou combinés sur les transferts couplés d'eau et de saccharose et les principaux critères de qualité de fruit (écart de couleur, teneur en phénols totaux (PT), teneur en acide ascorbique (AA), retrait volumique, activité de l'eau) en prenant la poire Conférences comme modèle. L'effet des procédés sur les morceaux de poire a été appréhendé selon deux approches : (i) une étude globale de l'impact des variables de commandes sur la qualité du produit fini et (ii) une étude cinétique des composés d'intérêt nutritionnel et de la qualité (couleur, retrait, activité de l'eau).Un plan d'expériences composite centré à quatre facteurs et cinq niveaux a été établi (concentration en saccharose de la solution osmotique : 25-65%, température de DII : 20-60 °C, durée de la DII : 0,5-6,5 h, température du séchage convectif : 30-70 °C) pour étudier l'effet global des procédés sur le produit fini. En DII, les paramètres « °Brix, « durée » et « la température de la solution » ont un effet significatif (p < 0,01) sur les pertes en eau, le gain en soluté et les attributs de qualité de morceaux de poire. Les pertes en AA sont plus élevées que les pertes en PT et sont essentiellement dues à l'oxydation et à l'entraînement par l'eau. Durant le séchage convectif, les pertes en PT et en AA dépendent plus de la durée du procédé que de la température d'exposition. Elles atteignent respectivement 80% et 34% après 10 h de séchage à 30 °C. Le changement de couleur de morceaux de poire dépend de la durée et de la température de traitement et est plus prononcé en fin de séchage. Des modèles quadratiques prédictifs ont été proposés pour relier les variables de réponse (aw, différence de couleur, perte en PT et durée totale de traitement) aux paramètres opératoires des deux procédés étudiés. Cependant, la perte en AA décroit linéairement avec la durée de DII. Une optimisation multicritères en utilisant la méthodologie des surfaces de réponse (MSR) a été proposée (pertes minimales en PT et en AA, durée totale du traitement et différence de couleur réduites et une aw inférieure à 0,6) pour la combinaison DII/séchage. Les conditions optimales sont : solution osmotique à 28°C et 25°Brix, une durée de DII de 30 min et un séchage convectif à 60 °C. Par ailleurs, les effets de la température (30, 45 et 60 °C) et de l'imprégnation en saccharose par DII (10 et 65 min, 70°Brix, 30 °C) sur les isothermes de désorption et sur la température de transition vitreuse (Tg) de morceaux de poires, de pommes et d'abricots ont été déterminés. L'imprégnation en saccharose du tissu végétal atténue l'influence de la température sur sa capacité de sorption. Elle engendre un effet dépresseur de l'activité de l'eau et une augmentation de l'hygroscopicité de la poire, la pomme et l'abricot à température élevée. Les isothermes de désorption des abricots frais et enrichis en saccharose présentent un croisement des courbes marquant l'inversement de l'effet de la température sur les isothermes. La Tg dépend de la température, de la teneur en saccharose et de la teneur en eau des fruits. Pour une teneur en eau constante, l'augmentation de la température et la durée de DII se traduisent par l'augmentation de la Tg. Les digrammes de phase (Tg=f(X) et Tg=f(aw)) des fruits ont été établis à 30, 45 et 60°C et les teneurs en eau critiques ainsi que les activités d'eau critiques ont été déterminées. Une teneur en eau en fin de séchage inférieure ou égale à 0,02 g/g M.S. est recommandée pour l'obtention de morceaux de fruit stables aux niveaux microbiologique, physicochimique et rhéologique. / The aim of this work was the study of the impact of both drying processes: dehydration-impregnation by soaking (DIS) and convective drying performed separately or in combination on mass transfers of water and sucrose and on the main quality characteristics of the fruit (total difference of colour, total phenols (TP) and ascorbic acid (AA) contents, shrinking, water activity) by taking the pear Conference as a model. The processes effect on the pieces of pear was apprehended according two approaches: (i) a global study of the impact of the variables of commands on the quality of finished product and (ii) a kinetic study of nutritional compounds and the quality (colour, shrinkage, and water activity). Central Composite Design with four factors (sucrose concentration: 25-65 %, temperature: 20-60 °C, immersion time: 0.5-6.5 hr and drying temperature: 30-70 °C) at five levels each was used for pears processing. During DIS, the variables: immersion time, temperature and concentration of sucrose solution had a significant effect (p<0.01) in the loss of water, the solid gain and the quality attributes of pears. The losses in AA are higher than those in TP and are essentially due to the oxidation and the leaching with water. During the convective drying, the losses in TP and in AA depend more on the time of the process rather than the temperature of exposition. They reach respectively 80% and 34% after 10 h of drying at 30 °C. The color change of pear depends on the time and temperature of treatment and is more pronounced at the end of drying. Predictive and quadratic models were suggested to link the responses variables (aw, total colour difference, TP loss and total time treatment) to operational parameters of both studied processes. The losses in AA decrease linearly with the duration of DIS. A multicriteria optimization using response surface methodology (RSM) was proposed (minimal losses in TP and in AA, reduced total processing time and total difference in colour and an aw inferior to 0.6) for the combination DIS/convective drying. The optimal conditions are: osmotic solution at 28°C and 25°Brix, a DIS lasting 30 min and a convective drying at 60 °C. Otherwise, the temperature effects (30, 45 and 60 °C) and the sucrose impregnation by DIS (10 and 65 min, 70°Brix, 30 °C) upon the desorption isotherms and the transition temperature (Tg) of pears, apples and apricots were determined. The sucrose impregnation diminishes the influence of temperature on its sorption ability. It generates a depressing effect on water activity and a rise of pear hygroscopicity, apple and apricot at a high temperature. The desorption isotherms of fresh and sucrose impregnated apricot present a crossing of curves which mark the inverse of the effect of temperature on isotherms. The Tg depends on the temperature, the sucrose content and the fruit water content (X). For constant water content, the rise of temperature and of the duration de DIS result in the increase of Tg. The phase diagrams (Tg=f(X) et Tg=f(aw)) of fruits were established at 30, 45 and 60°C and the critical water content as well as the critical water activities were determined. Water content at the end of drying inferior or equal to 0.02 g/g d.b. is recommended to obtain stable fruit pieces at microbiological, physiochemical and rheological levels.

Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2016-07-27T13:08:18Z No. of bitstreams: 1 2011 - Queli Cristina Fidelis.pdf: 8250271 bytes, checksum: f51d246c251bca4327f02da1e892ff77 (MD5) / Made available in DSpace on 2016-07-27T13:08:18Z (GMT). No. of bitstreams: 1 2011 - Queli Cristina Fidelis.pdf: 8250271 bytes, checksum: f51d246c251bca4327f02da1e892ff77 (MD5) Previous issue date: 2011-02-25 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico, CNPq, Brasil. / This work describes the phytochemical study of the stems and leaves of Ouratea ferruginea Engl., Ochnaceae. The material for study was collected in the campus of Embrapa in Bel?m, Par? state, and identified by Dra Silvane Taveres Rodrigues. The compounds described in this phytochemistry investigation were isolated by the solvents partition and chromatographyc techniques of the extracts obtained by maceration at room temperature with hexane, ethyl acetate and methanol. The structures were determined through analysis of data provided by IR, 1H and 13C NMR (1D an 2D techniques), mass spectrometry including GCMS and HPLC-MS of natural compounds and some derivatives. From the stem dichloromethane extract friedelin, friedelinol, sitosterol, stigmasterol, campesterol, 3-b-O-Dglucopyranosyl- stigmasterol, 2,6-dimethoxy?benzoquinine, 2,6-dimethoxy-hydroquinone, the isoflavones: 5,4'-dihydroxy-7,3',5'-trimethoxy-isoflavone, 5-hydroxy-7,3',4',5'-tetramethoxyisoflavone, 5,4'-dihydroxy-7,3'-dimethoxy-isoflavone, 7,5-dihydroxy-3',4',5'-trimethoxyisoflavone, 7,5,4?-trihydroxy-3?,5?-dimethoxy-isoflavone, and ferulic and syringic aldehyde were isolated. From the dichloromethane partition of the methanol extract of the stem vanillic acid, 4 ((1E)-3-hydroxy-1-propenyl)-2-methoxyphenol and 3,5-dimethoxy-4-hydroxydihydrocinamaldehyde were isolated. From hexane fraction of methanol extract from the leaves lupeone was isolated, and from the dichloromethane methanol partition were identified the biflavonoids amentoflavone and 7-methyl-amentoflavone, known as sequoiaflavone, along with syringic acid. From the ethyl acetate of the methanol extracts partition the epicatechin which absolute configuration was defined by circular dichroism spectral analysis was isolated. The sequioflanove is been identified in Ochnaceae for the first time. From the polar fraction the total phenol were determined by adapted Folin-Denis and precipitation with casein methods and by NMR spectral analysis. / Este trabalho descreve o estudo fitoqu?mico de caule e folhas da esp?cie vegetal Ouratea ferruginea Engl, Ochnaceae. O material para estudo foi coletado no campus da Embrapa em Bel?m do Par? e identificado pela Dra Silvane Tavares Rodrigues. As subst?ncias descritas nesta investiga??o fitoqu?mica foram isoladas atrav?s de parti??o com solventes e t?cnicas cromatogr?ficos de extratos obtidos atrav?s de macera??o a frio com hexano, acetato de etila e metanol. As estruturas foram determinadas atrav?s da an?lise de dados fornecidos por espectrometria na regi?o do infravermelho, RMN 1H e 13C (t?cnicas 1D e 2D), de massas incluindo CG-EM e CLAE-EM das subst?ncias naturais e de alguns derivados. Do extrato em diclorometano do caule foram isolados friedelina, friedelinol, sitosterol, estigmasterol, campesterol, 3-b-O-D-glicopiranosil-estigmasterol, 2,6-dimetoxi benzoquinona, 2,6-dimetoxi hidroquinona, as isoflavonas 5,4?-diidroxi-7,3?,5?-trimetoxiisoflavona, 5,4?-diidroxi-7,3?-dimetoxi-isoflavona, 5-hidroxi-7,3?,4?,5?-tetrametoxiisoflavona, 7,5-diidroxi-3?,4?,5?-trimetoxi-isoflavona, 7,5,4?-triidroxi-3?,5?-dimetoxiisoflavona, al?m dos alde?dos sir?ngico e fer?lico. Da parti??o em diclorometano do extrato metan?lico do caule foram isolados ?cido van?lico, 4((1E)-3-hidroxi-1-propenil)-2- metoxifenol e 3,5-dimetoxi-4-hidroxi-diidrocinamalde?do. Das folhas foi isolada a lupeona na parti??o em hexano do extrato metan?lico; e na parti??o em diclorometano foram identificados os biflavon?ides amentoflavona e 7-metil-amentoflavona, conhecida como sequoiaflavona, e o ?cido sir?ngico. Na parti??o em acetato de etila foi isolado a epicatequina cuja configura??o absoluta foi definida com an?lise do espectro de dicro?smo circular. A sequioflavona est? sendo registrada pela primeira vez em Ochnaceae. Das fra??es polares foram determinados o teor de fen?is totais e taninos por m?todos de Folin-Denis e precipita??o com case?na, adaptados, al?m de an?lise com espectros de RMN.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / Sulphur compounds can interfere with product quality of the wine, since they have a characteristic undesirable odor. The ethanethiol is considered an interesting compound from the electrochemical point of view, since it can become oxidized or reduced and thus, it can be studied both on polarized electrode surfaces and redox solutions. Therefore, the present work was divided in the study of reaction mechanism of ethanethiol on polarized electrode (gold electrode) and the study of the ethanethiol behavior in the redox system in solution (wine). The first part was developed by applying techniques such as cyclic voltammetry, differential pulse and atomic force microscopy. This allowed a complete characterization of ethanethiol on electrochemical gold electrode in alkaline medium with respect to its reaction mechanism, and also a large morphological characterization of the gold electrode. In the second part of the work a study about the ethanethiol influence on the antioxidant activity of compounds present in wine (resveratrol and gallic acid) and its influence in the antioxidant activity and in the concentration of phenolic compounds in wine was carried out. The wines were: Cabernet Suavignon Cabernet (2012 and 2006), Merlot (2012 and 2008), Pinot noir red and rose (2012) and Chardonnay (2011). Moreover, the electroanalytical determination of the ethanethiol (representing the class of low molecular weight thiols), inorganic sulfide and sulfite, using the stripping voltammetry and cathodic electrode mercury drop in acid medium, was carried out. / Compostos de enxofre podem interferir na qualidade do produto final do vinho, uma vez que apresentam odor indesejável característico. O etanotiol é considerado um composto interessante do ponto de vista eletroquímico, uma vez que pode se oxidar ou se reduzir podendo então ser estudado tanto em superfícies de eletrodos polarizados quanto em uma solução redox. Sendo assim, o presente trabalho foi dividido no estudo do mecanismo reacional do etanotiol em eletrodo polarizado (eletrodo de ouro) e o estudo do comportamento do etanotiol frente a sistema redox em solução (vinho). A primeira parte foi desenvolvida aplicando-se técnicas como voltametria cíclica, de pulso diferencial e microscopia de força atômica. Isto possibilitou obter uma completa caracterização eletroquímica do etanotiol no eletrodo de ouro em meio alcalino, no que se refere ao mecanismo reacional do mesmo, e também uma ampla caracterização morfológica do eletrodo de ouro. Na segunda parte do trabalho realizou-se o estudo da influência do etanotiol na atividade antioxidante de compostos presentes no vinho (resveratrol e ácido gálico), assim como sua influência na atividade antioxidante e na concentração de fenóis totais no vinho. Os vinhos estudados foram: Cabernet Suavignon safras 2012 e 2006, Merlot safras 2012 e 2008, Pinot noir tinto e rose safra 2012, Chardonnay safra 2011. Além disso, realizou-se a determinação eletroanalítica de etanotiol (representando a classe de tióis de baixo peso molecular), sulfeto inorgânico e sulfito, utilizando-se a voltametria de redissolução catódica e eletrodo de mercúrio de gota pendente em meio ácido.