2,567 research outputs found

    Preliminary Characterisation of Sardinian Red Grape Cultivars (Vitis vinifera L.) According to Their Phenolic Potential

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    Fourteen cultivars and clones, mainly selected from the island of Sardinia (Italy) and grown in a collection field,showed significant quantitative differences in phenolic potential. An extraction method designed to reproducethe winemaking process was used to determine the amounts of extractable polyphenols, anthocyanins, catechinsand proanthocyanidins reactive to vanillin, and the proanthocyanidins in grape skins and seeds. The Sardiniancultivar Nieddera and the Spanish cultivar Graciano had the highest concentrations of extractable polyphenols,anthocyanins, catechins and proanthocyanidins reactive to vanillin. Four clones of the Cannonau cultivar (synonymGrenache) exhibited fairly high variability, with significant differences in berry and seed phenolic contents

    Free and Enzymatically Hydrolysed Volatile Compounds of Sweet Wines from Malvasia and Muscat Grapes (Vitis vinifera L.) Grown in Sardinia

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    The aroma of Muscat of Sorso-Sennori and Malvasia di Bosa wines obtained from grapes grown in Sardinia wasevaluated by instrumental analysis. Gas chromatography/mass spectrometry was used to identify and quantifythe content of free and bound volatile compounds. The odour activity value (OAV) was also calculated. Higheralcohols and esters were quantitatively the largest group of free volatile compounds in both wines, while terpeneswere the main class of bound volatiles. A total of 52 free and 26 bound volatiles were detected. Malvasia di Bosasweet wine had a higher content of alcohols, esters and acids in comparison to Muscat of Sorso-Sennori, whichwas richer in some terpenes, like nerol, geraniol and geranic acid, and also in bound volatile compounds. Atotal of 12 compounds were above the OAV. The main aroma-active compounds of Muscat were 3-methylbutylacetate (banana), ethyl octanoate and hexanoate (fruity), and linalool (flowery), Malvasia wine was characterisedparticularly by ethyl octanoate and by 3-methylbutyl acetate

    Effect of Bottle Storage on Colour, Phenolics and Volatile Composition of Malvasia and Moscato White Wines

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    The effect of bottle storage on the colour, phenolics and volatile composition of Malvasia and Muscat winesobtained from grapes grown in Sardinia was evaluated. Colour was evaluated by UV-VIS spectrophotometryand by tristimulus colorimetry. Polyphenols were analysed by UV-VIS spectrophotometry and HPLCDAD.GC/MS was used to identify and quantify the content of free and bound volatile compounds. Asexpected, the absorbance values at 420 nm increased significantly for both wines during storage, due tooxidative browning, while difference in colour (DE*) from the beginning of storage and after 18 monthswas more intense in the Muscat wine than in the Malvasia wine. A significant decrease was observed indifferent phenolic compounds over time, especially in the Malvasia wine. In-bottle storage for 18 monthsat 20°C in the dark resulted in a significant decrease in all the classes of free and bound volatiles. Thesefinding enhance knowledge regarding the effects of bottle storage on Muscat and Malvasia wines. Thisis of interest because, rather surprisingly, this topic has been poorly investigated in relation to these twovarieties

    Evolución de la textura y capacidad antioxidante de aceitunas de mesa procesadas al natural con diferentes concentraciones de cloruro de sodio

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    The results on the evolution of the texture and antioxidant activity during the processing of naturally fermented green olives are reported in the present study. The olives were brined with two different NaCl concentrations, 4 and 7%. A puncture test and a texture profile analysis (TPA) test were carried out to evaluate texture, while the antioxidant activity was assessed in consideration of the loss of absorbance of a stable radical upon reaction with a polyphenolic olive extract. The puncture test revealed both an increase and decrease in peel and flesh hardness, respectively. The olives processed with 7% NaCl concentration showed higher peel hardness than olives brined with 4% salt. The texture profile analysis did not reveal any difference between the two salt concentrations used, but showed a decrease in the value of all parameters after 30 days of brining. The antioxidant activity of the polyphenolic extract decreased significantly during processing, with a major loss after the first 30 days of processing and was higher in the 7% brined olives, than the sample treated with 4% NaCl.En este trabajo se presentan los resultados sobre la evolución de la textura y la actividad antioxidante durante el proceso de fermentación natural de las aceitunas verdes. Los frutos se colocaron en salmueras con dos concentraciones de NaCl del 4% y 7%. Se evaluó la textura mediante ensayo de perforación y mediante análisis de perfil de textura (TPA), mientras que la actividad antioxidante se evaluó considerando la pérdida de absorbancia de un radical estable tras la reacción con un extracto polifenólico de las aceitunas. El ensayo de perforación reveló un aumento de la dureza de la piel y una reducción en la dureza de la pulpa. Las aceitunas procesadas con una concentración de NaCl del 7% mostraron una dureza mayor que aquellas tratadas con sal al 4%. El análisis del perfil de la textura no reveló diferencias entre las dos concentraciones usadas de sal, pero mostró una disminución en el valor de todos los parámetros después del primer mes de salmuera. La actividad antioxidante del extracto polifenólico disminuyó significativamente durante el tratamiento, con una pérdida importante después de los primeros 30 días de tratamiento y fue más alto en las aceitunas del 7% en salmuera respecto a las muestras tratadas con el 4% de NaCl

    intra varietal agronomical variability in vitis vinifera l cv cannonau investigated by fluorescence texture and colorimetric analysis

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    To date, innovative, rapid and non-invasive techniques have been used to assess variations in morphological and technological characteristics between grape cultivars. In order to improve knowledge of the qualitative expression of the genetic traits of cv. Cannonau (syn. Grenache), fluorescence, texture and colorimetric analyses were performed on 85 biotypes attributable to this variety. Eighty-five Cannonau biotypes cultivated in the same vineyard were analysed in order to evaluate their morphological and agronomical characteristics. As regards the morphological traits, of the six descriptors observed, five were able to discriminate the Cannonau population according to different expression levels. Must composition, berry colour (using the Minolta tristimulus colorimeter), texture (assessed using the TaxT2i plus texturimeter) and fluorescence (using the Multiplex III detector) were determined on clusters harvested at the same time. Cluster analysis was able to separate the Cannonau population into five groups, characterised by differences in the following criteria: L*, a* and b*, berry skin thickness, FERARI, TSS, pH and titratable acidity, total polyphenols and total anthocyanins. The FERARI index was highly and positively correlated with total anthocyanins and negatively correlated with grape colour, while berry weight and berry skin thickness were not correlated with any variable assessed. The remarkable intra-variability encountered for the qualitative and quantitative characters in the Cannonau variety suggests that new biotypes could be selected for different oenological purposes, using techniques such as the measure of fluorescence and colorimetry. This is the first study carried out within the cv. Cannonau using innovative and classical techniques suitable to investigate intra-varietal variability

    New insights into the bioavailability of red raspberry anthocyanins and ellagitannins

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    Red raspberries, containing ellagitannins and cyanidin-based anthocyanins, were fed to volunteers and metabolites appearing in plasma and urine were analysed by UHPLC-MS. Anthocyanins were not absorbed to any extent with sub nmol/L concentrations of cyanidin-3-O-glucoside and a cyanidin-O-glucuronide appearing transiently in plasma. Anthocyanins excreted in urine corresponded to 0.007% of intake. More substantial amounts of phase II metabolites of ferulic acid and isoferulic acid, along with 4′-hydroxyhippuric acid, potentially originating from pH-mediated degradation of cyanidin in the proximal gastrointestinal tract, appeared in urine and also plasma where peak concentrations were attained 1–1.5 h after raspberry intake. Excretion of 18 anthocyanin-derived metabolites corresponded to 15.0% of intake, a figure substantially higher than obtained in other anthocyanin feeding studies. Ellagitannins pass from the small to the large intestine where the colonic microbiota mediate their conversion to urolithins A and B which appeared in plasma and were excreted almost exclusively as sulfate and glucuronide metabolites. The urolithin metabolites persisted in the circulatory system and were excreted in urine for much longer periods of time than the anthocyanin metabolites although their overall urinary recovery was lower at 7.0% of intake. It is events originating in the proximal and distal gastrointestinal tract, and subsequent phase II metabolism, that play an important role in the bioavailability of both anthocyanins and ellagitannins and it is their metabolites which appear in the circulatory system, that are key to elucidating the mode of action(s) underlying the protective effects of these compounds on human health

    Association of patients' geographic origins with viral hepatitis co-infection patterns, Spain

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    To determine if hepatitis C virus seropositivity and active hepatitis B virus infection in HIV-positive patients vary with patients' geographic origins, we studied co-infections in HIV-seropositive adults. Active hepatitis B infection was more prevalent in persons from Africa, and hepatitis C seropositivity was more common in persons from eastern Europe.Ministerio de Sanidad. Instituto de Salud Carlos II

    Effect of ripening stage at harvest, cold storage, and simulated marketing conditions on quality and antioxidant activity of peach fruit

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    The influence of storage time on different quality parameters and in vitro antioxidant activity of peaches cv. Elegant Lady harvested at two ripening stages (immature and commercial mature) and stored under cold and marketing conditions were assessed. Destructive (physical-chemical properties, antioxidant activity, and firmness) and non-destructive parameters (colour and index of absorbance difference, IAD) were assessed. Storage and ripening stage influenced firmness, colour, and antioxidant activity. Firmness decreased significantly during cold and marketing storage, and skin colour parameters, a* and b*, underwent a deepening of the red hue, while IAD values fully justified differences in colour over storage time and ripening stage. The antioxidant activity increased during storage, although polyphenols and ascorbic acid contents remained constant, and was higher in commercial mature fruit than immature peaches, that revealed a ratio of total sugars/total acids more equilibrated

    Melt-spun bioactive sutures containing nanohybrids for local delivery of anti-inflammatory drugs.

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    In this work, a novel concept is introduced in drug-eluting fibres to ensure a good control of drug delivery features and wide applicability to different bioactive compounds. Composite bioactive sutures based on fibre grade poly(ε-caprolactone) (PCL) and loaded with the anti-inflammatory drug Diclofenac (Dic) or a Dic nanohybrid where the drug is intercalated in a synthetic hydrotalcite (Mg/Al hydroxycarbonate) (HT-Dic) were developed. Fibres were prepared by melt-spinning at different PCL/HT-Dic/Dic ratios and analysed in terms of morphology, mechanical properties and drug release features. Results emphasized that tensile properties of fibres are clearly affected by Dic or HT-Dic addition, while the presence of knots has limited influence on the mechanical behaviour of the sutures. Release of Dic strongly depends on how Dic is loaded in the fibre (as free or nanohybrid) whereas the combination of free Dic and HT-Dic can allow a further tuning of release profile. In vivo experiments show a reduction of inflammatory responses associated with Dic-loaded fibers. Thus, a proof of principle is provided for a novel class of bioactive sutures integrating advanced controlled-release technologies

    Cálculo de la longitud mínima de aproximación para una canaleta Parshall a través de la comparación del comportamiento hidráulico entre un modelo numérico y un modelo físico

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    Trabajo de InvestigaciónLa canaleta Parshall es una estructura hidraulica de gran empleabilidad dentro del campo de la Ingenieria, uno de sus usos es aforador de caudal o instrumento medidor. Pero en medio de su funcionalidad presenta problemas a la hora de encontrar obstaculos a la entrada de la canaleta, lo que hace que se alteren las laminas de agua, causando grandes problemas a su funcionalidad. El presente estudio propone un analisis en la longitud de aproximacion a la entrada de la canaleta en donde al interponer obstaculos, no se causara ninguna interferencia a las laminas de agua. Para el estudio efectivo se utiliza la herramienta computacional OpenFoam, con el fin de de determinar que longitud es la más exacta para no alterar las condiciones del flujo. De la misma manera estos resultados son comparados con un modelo a escala de laboratorioINTRODUCCIÓN 1. GENERALIDADES 2. MARCO DE REFERENCIA 3. METODOLOGIA 4. RESULTADOS 5. CONCLUSIONES 6. RECOMENDACIONES 7. ANEXOS 8. BIBLIOGRAFIAPregradoIngeniero Civi
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