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Veraison
In viticulture, veraison (french: véraison, ) is the onset of the ripening of the grapes. The official definition of ''veraison'' is "change of color of the grape berries". Veraison represents the transition from berry growth to berry ripening, and many changes in berry development occur at veraison. Process Grape berries follow a double sigmoid growth curve. The initial phase of berry growth is a result of cell division and cell expansion. As berry growth of phase I slows this is termed the lag phase. The lag phase is not a physiological growth stage, but an artificial designation between the two growth periods of grape berry development. Post-veraison, fruit acidity decreases due to degradation of malic acid. The degradation of malic acid during ripening makes tartaric acid the predominant acid; grape berries also possess a small amount of citric acid. Tartaric acid accumulates early in phase I of berry growth, while malic acid accumulates at the end of phase I berry grow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Berry Ripening (wine)
In viticulture, ripeness is the completion of the ripening process of wine grapes on the vine which signals the beginning of harvest. What exactly constitutes ripeness will vary depending on what style of wine is being produced ( sparkling, still, fortified, ''rosé'', dessert wine, etc.) and what the winemaker and viticulturist personally believe constitutes ripeness. Once the grapes are harvested, the physical and chemical components of the grape which will influence a wine's quality are essentially set so determining the optimal moment of ripeness for harvest may be considered the most crucial decision in winemaking.J. Cox ''"From Vines to Wines"'' Fourth Edition, pg 97-106 Storey Publishing 1999 There are several factors that contribute to the ripeness of the grape. As the grapes go through ''veraison'', sugars in the grapes will continue to rise as acid levels fall. The balance between sugar (as well as the potential alcohol level) and acids is considered one of the most c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annual Growth Cycle Of Grapevines
The annual growth cycle of grapevines is the process that takes place in the vineyard each year, beginning with bud break in the spring and culminating in leaf fall in autumn followed by winter dormancy. From a winemaking perspective, each step in the process plays a vital role in the development of grapes with ideal characteristics for making wine. Viticulturalists and vineyard managers monitor the effect of climate, vine disease and pests in facilitating or impeding the vine's progression from bud break, flowering, fruit set, veraison, harvesting, leaf fall and dormancy-reacting if need be with the use of viticultural practices like canopy management, irrigation, vine training and the use of agrochemicals. The stages of the annual growth cycle usually become observable within the first year of a vine's life. The amount of time spent at each stage of the growth cycle depends on a number of factors-most notably the type of climate (warm or cool) and the characteristics of the grap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Véraison
In viticulture, veraison (french: véraison, ) is the onset of the ripening of the grapes. The official definition of ''veraison'' is "change of color of the grape berries". Veraison represents the transition from berry growth to berry ripening, and many changes in berry development occur at veraison. Process Grape berries follow a double sigmoid growth curve. The initial phase of berry growth is a result of cell division and cell expansion. As berry growth of phase I slows this is termed the lag phase. The lag phase is not a physiological growth stage, but an artificial designation between the two growth periods of grape berry development. Post-veraison, fruit acidity decreases due to degradation of malic acid. The degradation of malic acid during ripening makes tartaric acid the predominant acid; grape berries also possess a small amount of citric acid. Tartaric acid accumulates early in phase I of berry growth, while malic acid accumulates at the end of phase I berry grow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fruit Acidity
The acids in wine are an important component in both winemaking and the finished product of wine. They are present in both grapes and wine, having direct influences on the color, balance and taste of the wine as well as the growth and vitality of yeast during fermentation and protecting the wine from bacteria. The measure of the amount of acidity in wine is known as the “ titratable acidity” or “total acidity”, which refers to the test that yields the total of all acids present, while strength of acidity is measured according to pH, with most wines having a pH between 2.9 and 3.9. Generally, the lower the pH, the higher the acidity in the wine. There is no direct connection between total acidity and pH (it is possible to find wines with a high pH for wine and high acidity). In wine tasting, the term “acidity” refers to the fresh, tart and sour attributes of the wine which are evaluated in relation to how well the acidity balances out the sweetness and bitter components ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xylem
Xylem is one of the two types of transport tissue in vascular plants, the other being phloem. The basic function of xylem is to transport water from roots to stems and leaves, but it also transports nutrients. The word ''xylem'' is derived from the Ancient Greek word (''xylon''), meaning "wood"; the best-known xylem tissue is wood, though it is found throughout a plant. The term was introduced by Carl Nägeli in 1858. Structure The most distinctive xylem cells are the long tracheary elements that transport water. Tracheids and vessel elements are distinguished by their shape; vessel elements are shorter, and are connected together into long tubes that are called ''vessels''. Xylem also contains two other type of cells: parenchyma and fibers. Xylem can be found: * in vascular bundles, present in non-woody plants and non-woody parts of woody plants * in secondary xylem, laid down by a meristem called the vascular cambium in woody plants * as part of a stelar arrangement n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Châteauneuf-du-Pape
Châteauneuf-du-Pape (; Provençal: Castèu-Nòu-De-Papo) is a commune in the Vaucluse department in the Provence-Alpes-Côte d'Azur region in Southeastern France. The village lies about to the east of the Rhône and north of the town of Avignon. As of 2019 the commune had a population of 2,055. A ruined medieval castle sits above the village and dominates the landscape to the south. It was built in the 14th century for Pope John XXII, the second of the popes to reside in Avignon. None of the subsequent Avignon popes stayed in Châteauneuf but after the schism of 1378 the antipope Clement VII sought the security of the castle. With the departure of the popes the castle passed to the archbishop of Avignon, but it was too large and too expensive to maintain and was used as a source of stone for building work in the village. At the time of the Revolution the buildings were sold off and only the donjon was preserved. During the Second World War an attempt was made to demolish the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xanthophyll
Xanthophylls (originally phylloxanthins) are yellow pigments that occur widely in nature and form one of two major divisions of the carotenoid group; the other division is formed by the carotenes. The name is from Greek (, "yellow") and (, "leaf"), due to their formation of the yellow band seen in early chromatography of leaf pigments. Molecular structure As both are carotenoids, xanthophylls and carotenes are similar in structure, but xanthophylls contain oxygen atoms while carotenes are ''purely hydrocarbons'', which do not contain oxygen. Their content of oxygen causes xanthophylls to be more polar (in molecular structure) than carotenes, and causes their separation from carotenes in many types of chromatography. (Carotenes are usually more orange in color than xanthophylls.) Xanthophylls present their oxygen either as hydroxyl groups and/or as hydrogen atoms substituted by oxygen atoms when acting as a bridge to form epoxides. Occurrence Like other carotenoids, xanth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anthocyanin
Anthocyanins (), also called anthocyans, are water-soluble vacuolar pigments that, depending on their pH, may appear red, purple, blue, or black. In 1835, the German pharmacist Ludwig Clamor Marquart gave the name Anthokyan to a chemical compound that gives flowers a blue color for the first time in his treatise "''Die Farben der Blüthen''". Food plants rich in anthocyanins include the blueberry, raspberry, black rice, and black soybean, among many others that are red, blue, purple, or black. Some of the colors of autumn leaves are derived from anthocyanins. Anthocyanins belong to a parent class of molecules called flavonoids synthesized via the phenylpropanoid pathway. They occur in all tissues of higher plants, including leaves, stems, roots, flowers, and fruits. Anthocyanins are derived from anthocyanidins by adding sugars. They are odorless and moderately astringent. Although approved as food and beverage colorant in the European Union, anthocyanins are not approved ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carotenoids
Carotenoids (), also called tetraterpenoids, are yellow, orange, and red organic pigments that are produced by plants and algae, as well as several bacteria, and fungi. Carotenoids give the characteristic color to pumpkins, carrots, parsnips, corn, tomatoes, canaries, flamingos, salmon, lobster, shrimp, and daffodils. Carotenoids can be produced from fats and other basic organic metabolic building blocks by all these organisms. It is also produced by endosymbiotic bacteria in whiteflies. Carotenoids from the diet are stored in the fatty tissues of animals, and exclusively carnivorous animals obtain the compounds from animal fat. In the human diet, absorption of carotenoids is improved when consumed with fat in a meal. Cooking carotenoid-containing vegetables in oil and shredding the vegetable both increase carotenoid bioavailability. There are over 1,100 known carotenoids which can be further categorized into two classes, xanthophylls (which contain oxygen) and carote ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlorophyll
Chlorophyll (also chlorophyl) is any of several related green pigments found in cyanobacteria and in the chloroplasts of algae and plants. Its name is derived from the Greek words , ("pale green") and , ("leaf"). Chlorophyll allow plants to absorb energy from light. Chlorophylls absorb light most strongly in the blue portion of the electromagnetic spectrum as well as the red portion. Conversely, it is a poor absorber of green and near-green portions of the spectrum. Hence chlorophyll-containing tissues appear green because green light, diffusively reflected by structures like cell walls, is less absorbed. Two types of chlorophyll exist in the photosystems of green plants: chlorophyll ''a'' and ''b''. History Chlorophyll was first isolated and named by Joseph Bienaimé Caventou and Pierre Joseph Pelletier in 1817. The presence of magnesium in chlorophyll was discovered in 1906, and was that element's first detection in living tissue. After initial work done by German chemi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methoxypyrazines
Methoxypyrazines are a class of chemical compounds that produce odors. The odors tend to be undesirable, as in the case of certain wines, or as defensive chemicals used by insects such as ''Harmonia axyridis'' which produces isopropyl methoxy pyrazine (IPMP). They have also been identified as additives in cigarette manufacture. Detection thresholds are very low, typically near 2 parts per trillion (1 ng/L). Examples of methoxypyrazines in wine grapes Cabernet Sauvignon has high levels of methoxypyrazines.Oz Clarke ''Encyclopedia of Grapes'' pg 223 Harcourt Books 2001 Two methoxypyrazine compounds, 3-isobutyl-2-methoxypyrazine (IBMP) and 3-isopropyl-2-methoxypyrazine (IPMP), are considered to be important determinants of green flavours in Sauvignon blanc wines.Marais, J., Hunter, J.J., & Haasbroek, P.D. (1999). Effect of microclimate, season and region on Sauvignon blanc grape composition and wine quality. South African Journal of Enology and Viticulture, 20, 19-30. S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photosynthesis
Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored in carbohydrate molecules, such as sugars and starches, which are synthesized from carbon dioxide and water – hence the name ''photosynthesis'', from the Greek ''phōs'' (), "light", and ''synthesis'' (), "putting together". Most plants, algae, and cyanobacteria perform photosynthesis; such organisms are called photoautotrophs. Photosynthesis is largely responsible for producing and maintaining the oxygen content of the Earth's atmosphere, and supplies most of the energy necessary for life on Earth. Although photosynthesis is performed differently by different species, the process always begins when energy from light is absorbed by proteins called reaction centers that contain green chlorophyll (and other colored) pigments/chromoph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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