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Caftaric Acid
Caftaric acid is a non-flavonoid phenolic compound. It is found in the juice of grapes (''Vitis vinifera'') and impacts the color of white wine. It is an esterified phenolic acid, composed of caffeic acid, a hydroxycinnamate produced by plants, and tartaric acid, the principal organic acid found in grape berries. As such, caftaric acid is found in all grape juices and wines. During alcoholic and malolactic fermentation, the ester can be enzymatically hydrolysed, releasing the two constituents. Caffeic acid is susceptible to chemical oxidation, and subsequent redox reactions involving caffeic acid can contribute to wine browning over time, and the straw-gold color that can develop in some white wines after bottling. Aside from wine, it is abundantly present in raisins. It also occurs in ''Cichorium intybus'' (common chicory) and is one of the bioactive components of ''Echinacea purpurea'' (Eastern purple coneflower). Caftaric acid has a good bioavailability when fed in rats. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
White Wine
White wine is a wine that is Fermentation in winemaking, fermented without skin contact. The wine color, colour can be straw-yellow, yellow-green, or yellow-gold. It is produced by the alcoholic fermentation of the non-coloured Juice vesicles, pulp of grapes, which may have a skin of any colour. White wine has existed for at least 4,000 years. The wide variety of white wines comes from the large number of Varietal, varieties, methods of winemaking, and ratios of residual sugar. White wine is mainly from "white" grapes, which are green or yellow in colour, such as the Chardonnay, Sauvignon blanc and Riesling. Some white wine is also made from grapes with coloured skin, provided that the obtained wort is not stained. Pinot noir, for example, is commonly used to produce champagne. Among the many types of white wine, dry white wine is the most common. More or less aromatic and tangy, it is derived from the complete fermentation of the wort. Sweet wines, on the other hand, are produ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Winemaker
A winemaker or vintner is a person engaged in winemaking. They are generally employed by wineries or wine companies, where their work includes: *Cooperating with viticulturists *Monitoring the maturity of grapes to ensure their quality and to determine the correct time for harvest *Crushing and pressing grapes *Monitoring the settling of juice and the fermentation of grape material * Filtering the wine to remove remaining solids *Testing the quality of wine by tasting *Placing filtered wine in casks or tanks for storage and maturation *Preparing plans for bottling wine once it has matured *Making sure that quality is maintained when the wine is bottled Today, these duties require an increasing amount of scientific knowledge, since laboratory tests are gradually supplementing or replacing traditional methods. Winemakers can also be referred to as oenologists as they study oenology – the science of wine. Vintner A vintner is a wine merchant. In some modern use, particularly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chicoric Acid
Chicoric acid (also known as cichoric acid) is a hydroxycinnamic acid, an organic compound of the phenylpropanoid class and occurs in a variety of plant species. It is a derivative of both caffeic acid and tartaric acid. As a suitable marker for the distinction of ''Echinacea'' species, it is often assayed using RP-HPLC and Thin layer chromatography (TLC) methods. Sources Chicoric acid has first been isolated from ''Cichorium intybus'' (chicory) but also occurs in significant amounts in ''Echinacea'', in particular ''E. purpurea'', dandelion leaves, basil, lemon balm, and aquatic plants, including algae and seagrasses. Biological functions Chicoric acid has been shown to stimulate phagocytosis in both ''in vitro'' and ''in vivo'' studies, to inhibit the function of hyaluronidase (an enzyme that breaks down hyaluronic acid in the human body), to protect collagen from damage due to free radicals, and to inhibit the function of HIV-1 integrase. See also * Caftaric acid Caf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyphenol Oxidase
Polyphenol oxidase (PPO; also polyphenol oxidase i, chloroplastic), an enzyme involved in fruit browning, is a tetramer that contains four atoms of copper per molecule. PPO may accept monophenols and/or ''o''-diphenols as substrates. The enzyme works by catalyzing the ''o''-hydroxylation of monophenol molecules in which the benzene ring contains a single hydroxyl substituent to ''o''-diphenols (phenol molecules containing two hydroxyl substituents at the 1, 2 positions, with no carbon between). It can also further catalyse the oxidation of ''o''-diphenols to produce ''o''-quinones. PPO catalyses the rapid polymerization of ''o''-quinones to produce black, brown or red pigments (polyphenols) that cause fruit browning. The amino acid tyrosine contains a single phenolic ring that may be oxidised by the action of PPOs to form ''o''-quinone. Hence, PPOs may also be referred to as tyrosinases. Common foods producing the enzyme include mushrooms (''Agaricus bisporus''), appl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Malvidin 3-glucoside
Oenin is an anthocyanin. It is the 3-glucoside of malvidin. It is one of the red pigments found in the skin of purple grapes and in wine. Color stabilization of malvidin 3-glucoside at a higher pH can be explained by self-aggregation of the flavylium cation and copigmentation with the Z-chalcone form. In the presence of procyanidin C2, the red color of oenin appears more stable. However, the HPLC chromatogram shows a decrease in the amplitude of the peaks of oenin and procyanidin C2. Concomitantly, a new peak appears with a maximal absorption in the red region. This newly formed pigment probably comes from the condensation of oenin and procyanidin C2. Malvidin 3-glucoside alone is not oxidized in the presence of grape polyphenol oxidase, whereas it is degraded in the presence of a crude grape PPO extract and of caftaric acid forming anthocyanidin-caftaric acid adducts. See also * Phenolic compounds in wine * Wine color * Malvidin glucoside-ethyl-catechin Malvidin glucoside-et ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grape Reaction Product
The grape reaction product (GRP, GRP1 or 2-S- glutathionyl caftaric acid) is a phenolic compound explaining the disappearance of caftaric acid from grape must during processing. It is also found in aged red wines. Its enzymatic production by polyphenol oxidase is important in limiting the browning of musts, especially in white wine production. The product can be recreated in model solutions. Determining its concentration in wine is possible by mass spectrometry. S-Glutathionyl caftaric acid is itself oxidizable. It is not a substrate for grape polyphenol oxidase, but laccase from ''Botrytis cinerea'' can use it to form GRP2. Related molecules Other related molecules are ''trans''-caffeoyltartrate derivatives like GRP o-quinone and 2,5-di-S-glutathionyl cafteoyl tartrate (GRP2) or adducts with anthocyanidins. See also * Phenolic compounds in wine The phenolic content in wine refers to the phenolic compounds—natural phenol and polyphenols—in wine, which include a large ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Winemaking
Winemaking or vinification is the production of wine, starting with the selection of the fruit, its fermentation into alcohol, and the bottling of the finished liquid. The history of wine-making stretches over millennia. The science of wine and winemaking is known as oenology. A winemaker may also be called a vintner. The growing of grapes is viticulture and there are many varieties of grapes. Winemaking can be divided into two general categories: still wine production (without carbonation) and sparkling wine production (with carbonation – natural or injected). Red wine, white wine, and rosé are the other main categories. Although most wine is made from grapes, it may also be made from other plants. (See fruit wine.) Other similar light alcoholic drinks (as opposed to beer or Liquor, spirits) include mead, made by fermenting Honey#Fermentation, honey and water, cider ("apple cider"), made by fermenting the Apple juice, juice of apples, and perry ("pear cider"), made ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxidation
Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a decrease in the oxidation state. There are two classes of redox reactions: * ''Electron-transfer'' – Only one (usually) electron flows from the reducing agent to the oxidant. This type of redox reaction is often discussed in terms of redox couples and electrode potentials. * ''Atom transfer'' – An atom transfers from one substrate to another. For example, in the rusting of iron, the oxidation state of iron atoms increases as the iron converts to an oxide, and simultaneously the oxidation state of oxygen decreases as it accepts electrons released by the iron. Although oxidation reactions are commonly associated with the formation of oxides, other chemical species can serve the same function. In hydrogenation, C=C (and other) bonds ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fertaric Acid
Fertaric acid is a hydroxycinnamic acid found in wine and grapes. It is an ester formed from ferulic acid bound to tartaric acid. It is a metabolite of caftaric acid Caftaric acid is a non-flavonoid phenolic compound. It is found in the juice of grapes (''Vitis vinifera'') and impacts the color of white wine. It is an esterified phenolic acid, composed of caffeic acid, a hydroxycinnamate produced by plants ... after caftaric acid has been fed to rats. Fertaric acid is then found in plasma, kidney, and urine. References O-methylated hydroxycinnamic acids Hydroxycinnamic acid esters Vinylogous carboxylic acids {{aromatic-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caffeic Acid
Caffeic acid is an organic compound that is classified as a hydroxycinnamic acid. This yellow solid consists of both phenolic and acrylic functional groups. It is found in all plants because it is an intermediate in the biosynthesis of lignin, one of the principal components of woody plant biomass and its residues. Natural occurrences Caffeic acid can be found in the bark of ''Eucalyptus globulus'' the barley grain ''Hordeum vulgare'' and the herb ''Dipsacus asperoides''. It can also be found in the freshwater fern ''Salvinia molesta'' and in the mushroom ''Phellinus linteus''. Occurrences in food Free caffeic acid can be found in a variety of beverages, including brewed coffee at 0.13 mg per 100 ml and red wine at 2 mg per 100 ml. It is found at relatively high levels in herbs of the mint family, especially thyme, sage and spearmint (at about 20 mg per 100 g), and in spices, such as Ceylon cinnamon and star anise (at about 22 mg per 100 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
