31 research outputs found

    Tannins and Anthocyanins: From Their Origin to Wine Analysis – A Review

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    Anthocyanins and tannins are very important chemical compounds in the grape berry and the corresponding wine, as they greatly influence the colour, taste and maturation potential of the wine, as well as offer numerous health benefits. This review tries to establish the origin of anthocyanins andtannins by looking at metabolic pathways and attempting to establish a link between photosynthesis and the flavonoid biosynthetic pathway, the translocation thereof from leaves to berries, different methods toextract anthocyanins and tannins from wine and, in the end, the different analytical methods that can be used to analyse for anthocyanins and tannins

    Ascorbic Acid Derivatives in the Sauvignon Blanc Cultivar (Vitis vinifera L.) During Berry Development in the Wellington and Elgin Regions

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    The exposure of grapevines to unfavourable conditions such as drought, high or low temperature andpathogenic attack increases the production of reactive oxygen species, thus inducing oxidative stress.One of the most important non-enzymatic antioxidants is ascorbic acid, which is used by plants toprotect themselves against these toxic oxygen intermediates. DHA, DKG and threonate are ascorbic acidmetabolites that are found during ascorbic acid catabolism. This study was done in two regions, the onein Wellington, classified as a warmer climate, and the other in Elgin, classified as a cooler climate. Ineach region, two Sauvignon blanc vineyard blocks were selected, with north to south and east to west rowdirections. Vines were monitored during the growing season to investigate the trends in the development ofascorbic acid metabolites in both regions. Canopy management practices were done at different ripeningstages. Grape berries were sampled at different phenological stages according to the Eichhorn Lorenzscale: E-L 32, E-L 34, E-L 35, E-L 37 and E-L 38. Ascorbic acid derivative concentrations in the two regionsvaried significantly in that Elgin showed higher concentrations than Wellington at E-L 32 and E-L 38. Boththe cool and warm regions had high concentrations of threonate, with no significant difference amongstages of ripeness. The DHA, DKG and threonate levels were the highest at the E-L 32 phenological stagefor both regions, with no significant differences among the other phenological stages, especially for DHAderivative concentrations. No significant effect on the DHA, DKG and threonate levels of the grapes wasobserved between row directions in each region

    The Influence of Different Winemaking Techniques on the Extraction of Grape Tannins and Anthocyanins

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    The aim of this study was to determine the effect of different maceration techniques on the extractionof grape tannins and anthocyanins. Two cultivars (Cabernet Sauvignon and Shiraz) were harvested intwo different climatic regions (Durbanville and Simondium) at two different ripeness levels for the 2008and 2009 harvest seasons. Five basic winemaking processes were applied, namely a normal alcoholicfermentation (C), enzyme treatment (E), cold soaking (CM), post-maceration (PM), and a combinationof cold and post-maceration (CM+PM). At harvest the phenolic ripeness was determined with the Gloriesmethod, while the tannin concentration was determined with the methyl cellulose (MCP) method. Thegrapes in the warmer area had higher tannin levels than grapes harvested in the cooler area in both years.In the 2009 harvest season, the enzyme treatment extracted the highest levels of tannin. CM+PM showedthe best results of tannin extraction with early ripeness (Cabernet Sauvignon), and CM with fuller ripenessin the warm area. CM showed the best results with both early and fuller ripeness levels in the cooler area.PM showed the best results with the early ripeness levels, and the E treatment with the fuller ripenesslevels, in the warm area. CM+PM showed the best results with the early ripeness level in the cooler area,and varied results with the fuller ripeness levels. In both years, grapes from the cooler area containedmore anthocyanin than those from the warmer area. At a fuller ripeness level (2009) the treatments hadno effect

    Attempted Identification of Causal Constituents of Pink Discolouration in White Wines

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    The pinking phenomenon has been known in the wine world for the past 50 years. The phenomenonoccurs when a white wine turns pink under certain conditions. Since then, a Portuguese study foundmalvidin-3-O-glucoside in Siria grapes making a connection to anthocyanin as the causing agent. Control(K), naturally pinked (NP) and pink induced (PI) Sauvignon blanc wine samples were analysed by LCMSand WineScanTM (Fourier Transform Infrared – FTIR) after Solid Phase Extraction. The monomericanthocyanins were analysed by a pH differential method, and CieLab was used to differentiate colourdifferences between the control and pinked samples. It was found that malvidin-3-O-glucoside was belowthe threshold values to facilitate pinking in Sauvignon blanc wines. Petunidin-3-O-glucoside showed aslight peak in the LC-MS analysis, and together with the malvidin-3-O-glucoside, the potential to pinkthe white wines increased. FTIR results showed that phenols and anthocyanins absorption could not bedistinguished and that there were possibly other compounds involved in the pinking of white wines. Analysisby CieLab expressed the PI wines as a darker pink colour than the control wine and the absorbency valueat 500 nm was at least three times higher for PI than the control, showing the aggressive oxidative natureof H2O2 on wine

    Sensory Evaluation of Pinked Sauvignon Blanc Wines

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    Sensorial studies on pinked white wines have never been carried out. The aim of this study was to establishthe probability of an aroma and taste difference in pinked Sauvignon blanc wines using a triangular test.The issue of at which point a wine consumer can perceived the wine as pink was analysed using a rankingexperiment. The probability that a wine taster can detect oxidised and pink wines as a wine fault was alsoanalysed. It was found that the panellists could not detect anomaly samples by taste and aroma alone,although some noticed an oxidised aroma on the nose. The pink detection point was established at 0.03 AU.This point can be used to refine the detection point and the assay used. It was established that more than50% of the panellists could detect oxidised and pink wines as a wine fault. The study data can be used toeither train panellists to detect pinking as a wine fault, or to establish a potential new category for pinkSauvignon blanc wines

    Occupational exposure to chemicals and fetal growth: the Generation R Study

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    Background Developmental diseases, such as birth defects, growth restriction and preterm delivery, account for >25 of infant mortality and morbidity. Several studies have shown that exposure to chemicals during pregnancy is associated with adverse birth outcomes. The aim of this study was to identify whether occupational exposure to various chemicals might adversely influence intrauterine growth patterns and placental weight.Methods Associations between mat

    Nanoparticles for Applications in Cellular Imaging

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    In the following review we discuss several types of nanoparticles (such as TiO2, quantum dots, and gold nanoparticles) and their impact on the ability to image biological components in fixed cells. The review also discusses factors influencing nanoparticle imaging and uptake in live cells in vitro. Due to their unique size-dependent properties nanoparticles offer numerous advantages over traditional dyes and proteins. For example, the photostability, narrow emission peak, and ability to rationally modify both the size and surface chemistry of Quantum Dots allow for simultaneous analyses of multiple targets within the same cell. On the other hand, the surface characteristics of nanometer sized TiO2allow efficient conjugation to nucleic acids which enables their retention in specific subcellular compartments. We discuss cellular uptake mechanisms for the internalization of nanoparticles and studies showing the influence of nanoparticle size and charge and the cell type targeted on nanoparticle uptake. The predominant nanoparticle uptake mechanisms include clathrin-dependent mechanisms, macropinocytosis, and phagocytosis

    Fungal Planet description sheets: 1284–1382

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    Novel species of fungi described in this study include those from various countries as follows: Antartica, Cladosporium austrolitorale from coastal sea sand. Australia, Austroboletus yourkae on soil, Crepidotus innuopurpureus on dead wood, Curvularia stenotaphri from roots and leaves of Stenotaphrum secundatum and Thecaphora stajsicii from capsules of Oxalis radicosa. Belgium, Paraxerochrysium coryli (incl. Paraxerochrysium gen. nov.) from Corylus avellana. Brazil, Calvatia nordestina on soil, Didymella tabebuiicola from leaf spots on Tabebuia aurea, Fusarium subflagellisporum from hypertrophied floral and vegetative branches of Mangifera indica and Microdochium maculosum from living leaves of Digitaria insularis. Canada, Cuphophyllus bondii fromagrassland. Croatia, Mollisia inferiseptata from a rotten Laurus nobilis trunk. Cyprus, Amanita exilis oncalcareoussoil. Czech Republic, Cytospora hippophaicola from wood of symptomatic Vaccinium corymbosum. Denmark, Lasiosphaeria deviata on pieces of wood and herbaceousdebris. Dominican Republic, Calocybella goethei among grass on a lawn. France (Corsica) , Inocybe corsica onwetground. France (French Guiana) , Trechispora patawaensis on decayed branch of unknown angiosperm tree and Trechispora subregularis on decayed log of unknown angiosperm tree. Germany, Paramicrothecium sambuci (incl. Paramicrothecium gen. nov.)ondeadstemsof Sambucus nigra. India, Aureobasidium microtermitis from the gut of a Microtermes sp. termite, Laccaria diospyricola on soil and Phylloporia tamilnadensis on branches of Catunaregam spinosa. Iran, Pythium serotinoosporum from soil under Prunus dulcis. Italy, Pluteus brunneovenosus on twigs of broad leaved trees on the ground. Japan, Heterophoma rehmanniae on leaves of Rehmannia glutinosa f. hueichingensis. Kazakhstan, Murispora kazachstanica from healthy roots of Triticum aestivum. Namibia, Caespitomonium euphorbiae (incl. Caespitomonium gen. nov.)from stems of an Euphorbia sp. Netherlands, Alfaria junci, Myrmecridium junci, Myrmecridium juncicola, Myrmecridium juncigenum, Ophioceras junci, Paradinemasporium junci (incl. Paradinemasporium gen. nov.), Phialoseptomonium junci, Sporidesmiella juncicola, Xenopyricularia junci and Zaanenomyces quadripartis (incl. Zaanenomyces gen. nov.), fromdeadculmsof Juncus effusus, Cylindromonium everniae and Rhodoveronaea everniae from Evernia prunastri, Cyphellophora sambuci and Myrmecridium sambuci from Sambucus nigra, Kiflimonium junci, Saro cladium junci, Zaanenomyces moderatricis academiae and Zaanenomyces versatilis from dead culms of Juncus inflexus, Microcera physciae from Physcia tenella, Myrmecridium dactylidis from dead culms of Dactylis glomerata, Neochalara spiraeae and Sporidesmium spiraeae from leaves of Spiraea japonica, Neofabraea salicina from Salix sp., Paradissoconium narthecii (incl. Paradissoconium gen. nov.)from dead leaves of Narthecium ossifragum, Polyscytalum vaccinii from Vaccinium myrtillus, Pseudosoloacrosporiella cryptomeriae (incl. Pseudosoloacrosporiella gen. nov.)fromleavesof Cryptomeria japonica, Ramularia pararhabdospora from Plantago lanceolata, Sporidesmiella pini from needles of Pinus sylvestris and Xenoacrodontium juglandis (incl. Xenoacrodontium gen. nov. and Xenoacrodontiaceae fam. nov.)from Juglans regia. New Zealand, Cryptometrion metrosideri from twigs of Metrosideros sp., Coccomyces pycnophyllocladi from dead leaves of Phyllocladus alpinus, Hypoderma aliforme from fallen leaves Fuscopora solandri and Hypoderma subiculatum from dead leaves Phormium tenax. Norway, Neodevriesia kalakoutskii from permafrost and Variabilispora viridis from driftwood of Picea abies. Portugal, Entomortierella hereditatis from abio film covering adeteriorated limestone wall. Russia, Colpoma junipericola from needles of Juniperus sabina, Entoloma cinnamomeum on soil in grasslands, Entoloma verae on soil in grasslands, Hyphodermella pallidostraminea on a dry dead branch of Actinidia sp., Lepiota sayanensis onlitterinamixedforest, Papiliotrema horticola from Malus communis , Paramacroventuria ribis (incl. Paramacroventuria gen. nov.)fromleaves of Ribes aureum and Paramyrothecium lathyri from leaves of Lathyrus tuberosus. South Africa, Harzia combreti from leaf litter of Combretum collinum ssp. sulvense, Penicillium xyleborini from Xyleborinus saxesenii , Phaeoisaria dalbergiae from bark of Dalbergia armata, Protocreopsis euphorbiae from leaf litter of Euphorbia ingens and Roigiella syzygii from twigs of Syzygium chordatum. Spain, Genea zamorana on sandy soil, Gymnopus nigrescens on Scleropodium touretii, Hesperomyces parexochomi on Parexochomus quadriplagiatus, Paraphoma variabilis from dung, Phaeococcomyces kinklidomatophilus from a blackened metal railing of an industrial warehouse and Tuber suaveolens in soil under Quercus faginea. Svalbard and Jan Mayen, Inocybe nivea associated with Salix polaris. Thailand, Biscogniauxia whalleyi oncorticatedwood. UK, Parasitella quercicola from Quercus robur. USA , Aspergillus arizonicus from indoor air in a hospital, Caeliomyces tampanus (incl. Caeliomyces gen. nov.)fromoffice dust, Cippumomyces mortalis (incl. Cippumomyces gen. nov.)fromatombstone, Cylindrium desperesense from air in a store, Tetracoccosporium pseudoaerium from air sample in house, Toxicocladosporium glendoranum from air in a brick room, Toxicocladosporium losalamitosense from air in a classroom, Valsonectria portsmouthensis from airinmen'slockerroomand Varicosporellopsis americana from sludge in a water reservoir. Vietnam, Entoloma kovalenkoi on rotten wood, Fusarium chuoi inside seed of Musa itinerans , Micropsalliota albofelina on soil in tropical evergreen mixed forest sand Phytophthora docyniae from soil and roots of Docynia indica. Morphological and culture characteristics are supported by DNA barcodes
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