Proanthocyanidins are a class of polyphenols found in many plants, such as cranberry , blueberry , and grape seeds . Chemically, they are oligomeric flavonoids . Many are oligomers of catechin and epicatechin and their gallic acid esters . More complex polyphenols, having the same polymeric building block, form the group of condensed tannins .
109-477: Proanthocyanidins were discovered in 1947 by Jacques Masquelier, who developed and patented techniques for the extraction of oligomeric proanthocyanidins from pine bark and grape seeds . Proanthocyanidins are under preliminary research for the potential to reduce the risk of urinary tract infections (UTIs) by consuming cranberries, grape seeds or red wine . Proanthocyanidins, including the lesser bioactive and bioavailable polymers (four or more catechins), represent
218-449: A beam of electrons . This may cause some of the sample's molecules to break up into positively charged fragments or simply become positively charged without fragmenting. These ions (fragments) are then separated according to their mass-to-charge ratio, for example by accelerating them and subjecting them to an electric or magnetic field: ions of the same mass-to-charge ratio will undergo the same amount of deflection. The ions are detected by
327-486: A mass spectrum , a record of ions as a function of m/Q . Typically, some type of electron multiplier is used, though other detectors including Faraday cups and ion-to-photon detectors are also used. Because the number of ions leaving the mass analyzer at a particular instant is typically quite small, considerable amplification is often necessary to get a signal. Microchannel plate detectors are commonly used in modern commercial instruments. In FTMS and Orbitraps ,
436-754: A 12th-century document found in the Cairo Geniza . In Iran, a sour grape vinegar is used for making Shirazi salad . Winemaking from red and white grape flesh and skins produces substantial quantities of organic residues, collectively called pomace (also "marc"), which includes crushed skins, seeds, stems, and leaves generally used as compost . Grape pomace – some 10–30% of the total mass of grapes crushed – contains various phytochemicals , such as unfermented sugars, alcohol, polyphenols , tannins , anthocyanins , and numerous other compounds, some of which are harvested and extracted for commercial applications (a process sometimes called "valorization" of
545-541: A 2014 scientific opinion by the European Food Safety Authority rejected physiological evidence that cranberry PACs have a role in inhibiting bacterial pathogens involved in UTIs; 2) an updated 2023 Cochrane Collaboration review supported the use of cranberry products for the prevention of UTIs for certain groups. A 2017 systematic review concluded that cranberry products significantly reduced
654-400: A broad application, in practice have come instead to connote a specific or a limited number of instrument configurations. An example of this is isotope-ratio mass spectrometry (IRMS), which refers in practice to the use of a limited number of sector based mass analyzers; this name is used to refer to both the application and the instrument used for the application. An important enhancement to
763-443: A central, spindle shaped electrode. The electrode confines the ions so that they both orbit around the central electrode and oscillate back and forth along the central electrode's long axis. This oscillation generates an image current in the detector plates which is recorded by the instrument. The frequencies of these image currents depend on the mass-to-charge ratios of the ions. Mass spectra are obtained by Fourier transformation of
872-452: A database of botanical and food sources of proanthocyanidins. In nature, proanthocyanidins serve among other chemical and induced defense mechanisms against plant pathogens and predators , such as occurs in strawberries . Proanthocyanidin has low bioavailability, with 90% remaining unabsorbed from the intestines until metabolized by gut flora to the more bioavailable metabolites. Condensed tannins can undergo acid-catalyzed cleavage in
981-473: A day for women and two for men, may confer health benefits. Alcohol itself may have protective effects on the cardiovascular system. The consumption of grapes and raisins presents a potential health threat to dogs. Their toxicity to dogs can cause the animal to develop acute kidney failure (the sudden development of kidney failure) with anuria (a lack of urine production) and may be fatal. Christians have traditionally used wine during worship services as
1090-408: A device with perpendicular electric and magnetic fields that separated the positive rays according to their charge-to-mass ratio ( Q/m ). Wien found that the charge-to-mass ratio depended on the nature of the gas in the discharge tube. English scientist J. J. Thomson later improved on the work of Wien by reducing the pressure to create the mass spectrograph. The word spectrograph had become part of
1199-683: A dominant position of wine-making in human culture dates from 8,000 years ago in Georgia . The oldest known winery, the Areni-1 winery , was found in Armenia and dated back to around 4000 BC. By the 9th century AD, the city of Shiraz was known to produce some of the finest wines in the Middle East. Thus it has been proposed that Syrah red wine is named after Shiraz , a city in Persia where
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#17327721738911308-452: A five US fluid ounces (150 ml) serving of red wine averages 91 milligrams ( i.e. , 145.6 milligrams per 8 fl. oz. or 240 mL). Many other foods and beverages may also contain proanthocyanidins, but few attain the levels found in red grape seeds and skins, with a notable exception being aronia , which has the highest recorded level of proanthocyanidins among fruits assessed to date (664 milligrams per 100 g). Grape seed A grape
1417-582: A group of condensed flavan-3-ols, such as procyanidins , prodelphinidins and propelargonidins. They can be found in many plants, most notably apples , maritime pine bark and that of most other pine species, cinnamon , aronia fruit, cocoa beans , grape seed, grape skin (procyanidins and prodelphinidins ), and red wines of Vitis vinifera (the European wine grape). However, bilberry , cranberry , black currant , green tea , black tea , and other plants also contain these flavonoids. Cocoa beans contain
1526-608: A low solubility in water. They involve a moderate (50 to 90 °C) heating for a few minutes. Epimerisation may happen. Phloroglucinolysis can be used for instance for proanthocyanidins characterisation in wine or in grape seeds and skin. Thioglycolysis can be used to study proanthocyanidins or the oxidation of condensed tannins. It is also used for lignin quantitation . Reaction on condensed tannins from Douglas fir bark produces epicatechin and catechin thioglycolates . Condensed tannins from Lithocarpus glaber leaves have been analysed through acid-catalyzed degradation in
1635-414: A mass filter, to transmit a particular fragment ion to the detector. If a quadrupole is made to rapidly and repetitively cycle through a range of mass filter settings, full spectra can be reported. Likewise, a triple quad can be made to perform various scan types characteristic of tandem mass spectrometry . The quadrupole ion trap works on the same physical principles as the quadrupole mass analyzer, but
1744-775: A mass spectrometer. A collision cell then stabilizes the peptide ions while they collide with a gas, causing them to fragment by collision-induced dissociation (CID). A further mass analyzer then sorts the fragments produced from the peptides. Tandem MS can also be done in a single mass analyzer over time, as in a quadrupole ion trap . There are various methods for fragmenting molecules for tandem MS, including collision-induced dissociation (CID), electron capture dissociation (ECD), electron transfer dissociation (ETD), infrared multiphoton dissociation (IRMPD), blackbody infrared radiative dissociation (BIRD), electron-detachment dissociation (EDD) and surface-induced dissociation (SID). An important application using tandem mass spectrometry
1853-512: A means of remembering the blood of Jesus Christ which was shed for the remission of sins . Christians who oppose the partaking of alcoholic beverages sometimes use grape juice as the "cup" or "wine" in the Lord's Supper . The Catholic Church continues to use wine in the celebration of the Eucharist because it is part of the tradition passed down through the ages starting with Jesus Christ at
1962-495: A mechanism capable of detecting charged particles, such as an electron multiplier . Results are displayed as spectra of the signal intensity of detected ions as a function of the mass-to-charge ratio. The atoms or molecules in the sample can be identified by correlating known masses (e.g. an entire molecule) to the identified masses or through a characteristic fragmentation pattern. In 1886, Eugen Goldstein observed rays in gas discharges under low pressure that traveled away from
2071-585: A moderate amount of vitamin K (14% of the Daily Value ), with no other micronutrients in significant amounts. Most domesticated grapes come from cultivars of Vitis vinifera , a grapevine native to the Mediterranean and Central Asia. Minor amounts of fruit and wine come from American and Asian species such as: According to the Food and Agriculture Organization (FAO), 75,866 square kilometers of
2180-535: A multitude of products such as jams, juices, vinegars and oils. Commercially cultivated grapes are classified as either table or wine grapes. These categories are based on their intended method of consumption: grapes that are eaten raw (table grapes), or grapes that are used to make wine (wine grapes). Table grape cultivars normally have large, seedless fruit and thin skins. Wine grapes are smaller (in comparison to table grapes), usually contains seeds, and have thicker skins (a desirable characteristic in making wine). Most of
2289-471: A natural abundance of about 25 percent). The analyzer part of the spectrometer contains electric and magnetic fields, which exert forces on ions traveling through these fields. The speed of a charged particle may be increased or decreased while passing through the electric field, and its direction may be altered by the magnetic field. The magnitude of the deflection of the moving ion's trajectory depends on its mass-to-charge ratio. Lighter ions are deflected by
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#17327721738912398-435: A range of m/z to catalog the ions present. The time-of-flight (TOF) analyzer uses an electric field to accelerate the ions through the same potential , and then measures the time they take to reach the detector. If the particles all have the same charge , their kinetic energies will be identical, and their velocities will depend only on their masses . For example, ions with a lower mass will travel faster, reaching
2507-456: A relatively high phenolic content among dark grapes. In muscadine skins, ellagic acid , myricetin , quercetin , kaempferol , and trans-resveratrol are major phenolics. The flavonols syringetin , syringetin 3-O-galactoside, laricitrin and laricitrin 3-O-galactoside are also found in purple grape but absent in white grape. Muscadine grape seeds contain about twice the total polyphenol content of skins. Grape seed oil from crushed seeds
2616-631: A seeded variety as the female parent or rescue embryos early in development using tissue culture techniques. There are several sources of the seedlessness trait, and essentially all commercial cultivators get it from one of three sources: Thompson Seedless , Russian Seedless , and Black Monukka , all being cultivars of Vitis vinifera . There are currently more than a dozen varieties of seedless grapes. Several, such as Einset Seedless, Benjamin Gunnels's Prime seedless grapes, Reliance, and Venus, have been specifically cultivated for hardiness and quality in
2725-413: A static electric and/or magnetic field to affect the path and/or velocity of the charged particles in some way. As shown above, sector instruments bend the trajectories of the ions as they pass through the mass analyzer, according to their mass-to-charge ratios, deflecting the more charged and faster-moving, lighter ions more. The analyzer can be used to select a narrow range of m/z or to scan through
2834-460: A team of archaeologists concluded that Chalcolithic wine jars discovered in Cyprus in the 1930s dated back to 3500 BC, making them the oldest of their kind in the world. Commandaria , a sweet dessert wine from Cyprus, is the oldest manufactured wine in the world with origins as far back as 2000 BC. In North America, native grapes belonging to various species of the genus Vitis proliferate in
2943-414: A type of fruit that grow in clusters of 15 to 300 and can be crimson, black, dark blue, yellow, green, orange, and pink. "White" grapes are actually green in color and are evolutionarily derived from the purple grape. Mutations in two regulatory genes of white grapes turn off production of anthocyanins , which are responsible for the color of purple grapes. Anthocyanins and other pigment chemicals of
3052-506: A type of substitution reaction in organic chemistry , involving a carbocation intermediate under strongly acidic conditions in polar protic solvents like methanol. The reaction leads to the formation of free and derived monomers that can be further analyzed or used to enhance procyanidin absorption and bioavailability . The free monomers correspond to the terminal units of the condensed tannins chains. In general, reactions are made in methanol, especially thiolysis, as benzyl mercaptan has
3161-460: A wide array of sample types. In this source, a plasma that is electrically neutral overall, but that has had a substantial fraction of its atoms ionized by high temperature, is used to atomize introduced sample molecules and to further strip the outer electrons from those atoms. The plasma is usually generated from argon gas, since the first ionization energy of argon atoms is higher than the first of any other elements except He, F and Ne, but lower than
3270-475: Is MALDI-TOF , which refers to a combination of a matrix-assisted laser desorption/ionization source with a time-of-flight mass analyzer. Other examples include inductively coupled plasma-mass spectrometry (ICP-MS) , accelerator mass spectrometry (AMS) , thermal ionization-mass spectrometry (TIMS) and spark source mass spectrometry (SSMS) . Certain applications of mass spectrometry have developed monikers that although strictly speaking would seem to refer to
3379-449: Is a fruit , botanically a berry , of the deciduous woody vines of the flowering plant genus Vitis . Grapes are a non- climacteric type of fruit, generally occurring in clusters . The cultivation of grapes began approximately 8,000 years ago, and the fruit has been used as human food throughout its history. Eaten fresh or in dried form (as raisins , currants and sultanas ), grapes also hold cultural significance in many parts of
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3488-563: Is a testing method that measures the change in color when the product is mixed with certain chemicals. The greater the color changes, the higher the PCOs content is. However, the Procyanidolic Index is a relative value that can measure well over 100. Unfortunately, a Procyanidolic Index of 95 was erroneously taken to mean 95% PCO by some and began appearing on the labels of finished products. All current methods of analysis suggest that
3597-433: Is a type of plot of the ion signal as a function of the mass-to-charge ratio. These spectra are used to determine the elemental or isotopic signature of a sample, the masses of particles and of molecules , and to elucidate the chemical identity or structure of molecules and other chemical compounds . In a typical MS procedure, a sample, which may be solid, liquid, or gaseous, is ionized , for example by bombarding it with
3706-443: Is a wide variety of ionization techniques, depending on the phase (solid, liquid, gas) of the sample and the efficiency of various ionization mechanisms for the unknown species. An extraction system removes ions from the sample, which are then targeted through the mass analyzer and into the detector . The differences in masses of the fragments allows the mass analyzer to sort the ions by their mass-to-charge ratio. The detector measures
3815-492: Is an example of the linear ion trap. A toroidal ion trap can be visualized as a linear quadrupole curved around and connected at the ends or as a cross-section of a 3D ion trap rotated on edge to form the toroid, donut-shaped trap. The trap can store large volumes of ions by distributing them throughout the ring-like trap structure. This toroidal shaped trap is a configuration that allows the increased miniaturization of an ion trap mass analyzer. Additionally, all ions are stored in
3924-448: Is applied to the endcap electrodes, and the trapping voltage amplitude and/or excitation voltage frequency is varied to bring ions into a resonance condition in order of their mass/charge ratio. The cylindrical ion trap mass spectrometer (CIT) is a derivative of the quadrupole ion trap where the electrodes are formed from flat rings rather than hyperbolic shaped electrodes. The architecture lends itself well to miniaturization because as
4033-451: Is applied. This filament emits electrons which ionize the compounds. The ions can then further fragment, yielding predictable patterns. Intact ions and fragments pass into the mass spectrometer's analyzer and are eventually detected. However, the high temperatures (300 °C) used in the GC-MS injection port (and oven) can result in thermal degradation of injected molecules, thus resulting in
4142-704: Is believed that the most widely planted variety is Sultana , also known as Thompson Seedless, with at least 3,600 km (880,000 acres) dedicated to it. The second most common variety is Airén . Other popular varieties include Cabernet Sauvignon , Sauvignon blanc , Cabernet Franc , Merlot , Grenache , Tempranillo , Riesling , and Chardonnay . Commercially cultivated grapes can usually be classified as either table or wine grapes, based on their intended method of consumption: eaten raw (table grapes) or used to make wine (wine grapes). The sweetness of grapes depends on when they are harvested, as they do not continue to ripen once picked. While almost all of them belong to
4251-407: Is designed to pass the untrapped ions rather than collect the trapped ones, and is for that reason referred to as a transmission quadrupole. A magnetically enhanced quadrupole mass analyzer includes the addition of a magnetic field, either applied axially or transversely. This novel type of instrument leads to an additional performance enhancement in terms of resolution and/or sensitivity depending upon
4360-474: Is in protein identification. Tandem mass spectrometry enables a variety of experimental sequences. Many commercial mass spectrometers are designed to expedite the execution of such routine sequences as selected reaction monitoring (SRM), precursor ion scanning, product ion scanning, and neutral loss scanning. Another type of tandem mass spectrometry used for radiocarbon dating is accelerator mass spectrometry (AMS), which uses very high voltages, usually in
4469-408: Is not suitable for coupling to HPLC , i.e. LC-MS , since at atmospheric pressure, the filaments used to generate electrons burn out rapidly. Thus EI is coupled predominantly with GC , i.e. GC-MS , where the entire system is under high vacuum. Hard ionization techniques are processes which impart high quantities of residual energy in the subject molecule invoking large degrees of fragmentation (i.e.
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4578-402: Is now discouraged due to the possibility of confusion with light spectroscopy . Mass spectrometry is often abbreviated as mass-spec or simply as MS . Modern techniques of mass spectrometry were devised by Arthur Jeffrey Dempster and F.W. Aston in 1918 and 1919 respectively. Sector mass spectrometers known as calutrons were developed by Ernest O. Lawrence and used for separating
4687-485: Is the ratio of the m/z measurement error to the true m/z . Mass accuracy is usually measured in ppm or milli mass units . The mass range is the range of m/z amenable to analysis by a given analyzer. The linear dynamic range is the range over which ion signal is linear with analyte concentration. Speed refers to the time frame of the experiment and ultimately is used to determine the number of spectra per unit time that can be generated. A sector field mass analyzer uses
4796-692: Is used in cosmeceuticals and skincare products. Grape seed oil, including tocopherols ( vitamin E ) and high contents of phytosterols and polyunsaturated fatty acids such as linoleic acid , oleic acid , and alpha-linolenic acid . Resveratrol, a stilbene compound, is found in widely varying amounts among grape varieties, primarily in their skins and seeds. Muscadine grapes have about one hundred times higher concentration of stilbenes than pulp. Fresh grape skin contains about 50 to 100 micrograms of resveratrol per gram. Comparing diets among Western countries, researchers have discovered that, although French people tend to eat higher levels of animal fat,
4905-636: Is used to dissociate stable gaseous molecules in a carrier gas of He or Ar. In instances where a synchrotron light source is utilized, a tuneable photon energy can be utilized to acquire a photoionization efficiency curve which can be used in conjunction with the charge ratio m/z to fingerprint molecular and ionic species. More recently atmospheric pressure photoionization (APPI) has been developed to ionize molecules mostly as effluents of LC-MS systems. Some applications for ambient ionization include environmental applications as well as clinical applications. In these techniques, ions form in an ion source outside
5014-549: The Last Supper , where Catholics believe the consecrated bread and wine become the body and blood of Jesus Christ, a dogma known as transubstantiation . Wine is used (not grape juice) both due to its strong Scriptural roots, and also to follow the tradition set by the early Christian Church. The Code of Canon Law of the Catholic Church (1983), Canon 924 says that the wine used must be natural, made from grapes of
5123-476: The Red Delicious and Granny Smith varieties. An extract of maritime pine bark called Pycnogenol bears 65–75 percent proanthocyanidins (procyanidins). Thus a 100 mg serving would contain 65 to 75 mg of proanthocyanidins (procyanidins). Proanthocyanidin glycosides can be isolated from cocoa liquor . The seed testas of field beans ( Vicia faba ) contain proanthocyanidins that affect
5232-418: The anode and through channels in a perforated cathode , opposite to the direction of negatively charged cathode rays (which travel from cathode to anode). Goldstein called these positively charged anode rays "Kanalstrahlen"; the standard translation of this term into English is " canal rays ". Wilhelm Wien found that strong electric or magnetic fields deflected the canal rays and, in 1899, constructed
5341-464: The digestibility in piglets and could have an inhibitory activity on enzymes. Cistus salviifolius also contains oligomeric proanthocyanidins. (mg/100g) Condensed tannins may be characterised by a number of techniques including depolymerisation , asymmetric flow field flow fractionation or small-angle X-ray scattering . DMACA is a dye that is particularly useful for localization of proanthocyanidin compounds in plant histology. The use of
5450-425: The international scientific vocabulary by 1884. Early spectrometry devices that measured the mass-to-charge ratio of ions were called mass spectrographs which consisted of instruments that recorded a spectrum of mass values on a photographic plate . A mass spectroscope is similar to a mass spectrograph except that the beam of ions is directed onto a phosphor screen. A mass spectroscope configuration
5559-702: The isotopes of uranium during the Manhattan Project . Calutron mass spectrometers were used for uranium enrichment at the Oak Ridge, Tennessee Y-12 plant established during World War II. In 1989, half of the Nobel Prize in Physics was awarded to Hans Dehmelt and Wolfgang Paul for the development of the ion trap technique in the 1950s and 1960s. In 2002, the Nobel Prize in Chemistry
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#17327721738915668-465: The wine industry, grape juice that contains 7–23% of pulp, skins, stems and seeds is often referred to as " must ". In North America, the most common grape juice is purple and made from Concord grapes , while white grape juice is commonly made from Niagara grapes , both of which are varieties of native American grapes, a different species from European wine grapes. In California, Sultana (known there as Thompson Seedless) grapes are sometimes diverted from
5777-421: The (officially) dimensionless m/z , where z is the number of elementary charges ( e ) on the ion (z=Q/e). This quantity, although it is informally called the mass-to-charge ratio, more accurately speaking represents the ratio of the mass number and the charge number, z . There are many types of mass analyzers, using either static or dynamic fields, and magnetic or electric fields, but all operate according to
5886-559: The EU to use the term "dried vine fruit" in official documents. A raisin is any dried grape. While raisin is a French loanword , the word in French refers to the fresh fruit; grappe (from which the English grape is derived) refers to the bunch (as in une grappe de raisins ). A raisin in French is called raisin sec ("dry grape"). A currant is a dried Zante Black Corinth grape,
5995-538: The United States), but the word is now applied to raisins made from either white grapes or red grapes that are bleached to resemble the traditional sultana. Grape juice is obtained from crushing and blending grapes into a liquid. The juice is often sold in stores or fermented and made into wine , brandy , or vinegar . Grape juice that has been pasteurized, removing any naturally occurring yeast, will not ferment if kept sterile, and thus contains no alcohol. In
6104-475: The above differential equation. Each analyzer type has its strengths and weaknesses. Many mass spectrometers use two or more mass analyzers for tandem mass spectrometry (MS/MS) . In addition to the more common mass analyzers listed below, there are others designed for special situations. There are several important analyzer characteristics. The mass resolving power is the measure of the ability to distinguish two peaks of slightly different m/z . The mass accuracy
6213-406: The above expressions for the force applied to the ion yields: This differential equation is the classic equation of motion for charged particles . Together with the particle's initial conditions, it completely determines the particle's motion in space and time in terms of m/Q . Thus mass spectrometers could be thought of as "mass-to-charge spectrometers". When presenting data, it is common to use
6322-550: The actual PCO content of these products is much lower than 95%. Gel permeation chromatography (GPC) analysis allows separation of monomers from larger proanthocyanidin molecules. Monomers of proanthocyanidins can be characterized by analysis with HPLC and mass spectrometry . Condensed tannins can undergo acid-catalyzed cleavage in the presence of a nucleophile like phloroglucinol (reaction called phloroglucinolysis), thioglycolic acid (thioglycolysis), benzyl mercaptan or cysteamine (processes called thiolysis ) leading to
6431-494: The analyte is ionized by chemical ion-molecule reactions during collisions in the source. Two techniques often used with liquid and solid biological samples include electrospray ionization (invented by John Fenn ) and matrix-assisted laser desorption/ionization (MALDI, initially developed as a similar technique "Soft Laser Desorption (SLD)" by K. Tanaka for which a Nobel Prize was awarded and as MALDI by M. Karas and F. Hillenkamp ). In mass spectrometry, ionization refers to
6540-495: The aroma in wine is from the skin. Wine grapes tend to have a high sugar content. They are harvested at peak sugar levels (approximately 24% sugar by weight.) In comparison, commercially produced "100% grape juice" made from table grapes are normally around 15% sugar by weight. In most of Europe and North America, dried grapes are referred to as "raisins" or the local equivalent. In the UK, three different varieties are recognized, forcing
6649-854: The aroma, flavor, mouth-feel and astringency of red wines. In red wines, total OPC content, including flavan-3-ols ( catechins ), was substantially higher (177 mg/L) than that in white wines (9 mg/L). Proanthocyanidins found in the proprietary extract of maritime pine bark called Pycnogenol were not found (in 2012) to be effective as a treatment for any disease: Proanthocyanidins are present in fresh grapes, juice, red wine , and other darkly pigmented fruits such as cranberry , blackcurrant , elderberry , and aronia . Although red wine may contain more proanthocyanidins by mass per unit of volume than does red grape juice, red grape juice contains more proanthocyanidins per average serving size. An eight US fluid ounces (240 ml) serving of grape juice averages 124 milligrams proanthocyanidins, whereas
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#17327721738916758-415: The central location of the peaks, since the starting velocity of ions is generally centered at zero. To fix this problem, time-lag focusing/ delayed extraction has been coupled with TOF-MS. Quadrupole mass analyzers use oscillating electrical fields to selectively stabilize or destabilize the paths of ions passing through a radio frequency (RF) quadrupole field created between four parallel rods. Only
6867-517: The detector consists of a pair of metal surfaces within the mass analyzer/ion trap region which the ions only pass near as they oscillate. No direct current is produced, only a weak AC image current is produced in a circuit between the electrodes. Other inductive detectors have also been used. A tandem mass spectrometer is one capable of multiple rounds of mass spectrometry, usually separated by some form of molecule fragmentation. For example, one mass analyzer can isolate one peptide from many entering
6976-439: The detector first. Ions usually are moving prior to being accelerated by the electric field , this causes particles with the same m/z to arrive at different times at the detector. This difference in initial velocities is often not dependent on the mass of the ion, and will turn into a difference in the final velocity. This distribution in velocities broadens the peaks shown on the count vs m/z plot, but will generally not change
7085-424: The detector is located. Ions of different mass are resolved according to impact time. The final element of the mass spectrometer is the detector. The detector records either the charge induced or the current produced when an ion passes by or hits a surface. In a scanning instrument, the signal produced in the detector during the course of the scan versus where the instrument is in the scan (at what m/Q ) will produce
7194-567: The formation of oligomers that can be further analyzed. Tandem mass spectrometry can be used to sequence proanthocyanidins. Oligomeric proanthocyanidins (OPC) strictly refer to dimer and trimer polymerizations of catechins. OPCs are found in most plants and thus are common in the human diet. Especially the skin , seeds, and seed coats of purple or red pigmented plants contain large amounts of OPCs. They are dense in grape seeds and skin, and therefore in red wine and grape seed extract, cocoa, nuts and all Prunus fruits (most concentrated in
7303-521: The grape was used to make Shirazi wine . Ancient Egyptian hieroglyphics record the cultivation of purple grapes, and history attests to the ancient Greeks , Cypriots , Phoenicians , and Romans growing purple grapes both for eating and wine production. The growing of grapes would later spread to other regions in Europe, as well as North Africa, and eventually in North America . In 2005,
7412-404: The highest concentrations. Proanthocyanidins also may be isolated from Quercus petraea and Q. robur heartwood (wine barrel oaks ). Açaí oil , obtained from the fruit of the açaí palm ( Euterpe oleracea ), is rich in numerous procyanidin oligomers. Apples contain on average per serving about eight times the amount of proanthocyanidin found in wine, with some of the highest amounts found in
7521-459: The identification of known molecules it is also useful for identifying unknowns using its similarity searching/analysis. All tandem mass spectrometry data comes from the experimental analysis of standards at multiple collision energies and in both positive and negative ionization modes. When a specific combination of source, analyzer, and detector becomes conventional in practice, a compound acronym may arise to designate it succinctly. One example
7630-616: The incidence of heart disease remains low in France. This phenomenon has been termed the French paradox and is thought to occur due to the protective benefits of regularly consuming red wine, among other dietary practices. Alcohol consumption in moderation may be cardioprotective by its minor anticoagulant effect and vasodilation . Although adoption of wine consumption is generally not recommended by health authorities, some research indicates moderate consumption, such as one glass of red wine
7739-619: The incidence of UTIs, indicating that cranberry products may be effective particularly for individuals with recurrent infections. In 2019, the American Urological Association released guidelines stating that a moderate level of evidence supports the use of cranberry products containing PACs for possible prevention from recurrent UTIs. Proanthocyanidins are the principal polyphenols in red wine that are under research to assess risk of coronary heart disease and lower overall mortality. With tannins , they also influence
7848-403: The ions according to their mass-to-charge ratio . The following two laws govern the dynamics of charged particles in electric and magnetic fields in vacuum: Here F is the force applied to the ion, m is the mass of the ion, a is the acceleration, Q is the ion charge, E is the electric field, and v × B is the vector cross product of the ion velocity and the magnetic field Equating
7957-416: The ions are injected into a Penning trap (a static electric/magnetic ion trap ) where they effectively form part of a circuit. Detectors at fixed positions in space measure the electrical signal of ions which pass near them over time, producing a periodic signal. Since the frequency of an ion's cycling is determined by its mass-to-charge ratio, this can be deconvoluted by performing a Fourier transform on
8066-562: The ions are trapped and sequentially ejected. Ions are trapped in a mainly quadrupole RF field, in a space defined by a ring electrode (usually connected to the main RF potential) between two endcap electrodes (typically connected to DC or auxiliary AC potentials). The sample is ionized either internally (e.g. with an electron or laser beam), or externally, in which case the ions are often introduced through an aperture in an endcap electrode. There are many mass/charge separation and isolation methods but
8175-417: The ions in a certain range of mass/charge ratio are passed through the system at any time, but changes to the potentials on the rods allow a wide range of m/z values to be swept rapidly, either continuously or in a succession of discrete hops. A quadrupole mass analyzer acts as a mass-selective filter and is closely related to the quadrupole ion trap , particularly the linear quadrupole ion trap except that it
8284-502: The isotopic composition of its constituents (the ratio of Cl to Cl). The ion source is the part of the mass spectrometer that ionizes the material under analysis (the analyte). The ions are then transported by magnetic or electric fields to the mass analyzer. Techniques for ionization have been key to determining what types of samples can be analyzed by mass spectrometry. Electron ionization and chemical ionization are used for gases and vapors . In chemical ionization sources,
8393-421: The larger family of polyphenols in purple grapes are responsible for the varying shades of purple in red wines. Grapes are typically an ellipsoid shape resembling a prolate spheroid . Raw grapes are 81% water, 18% carbohydrates , 1% protein , and have negligible fat (table). A 100-gram ( 3 + 1 ⁄ 2 -ounce) reference amount of raw grapes supplies 288 kilojoules (69 kilocalories) of food energy and
8502-408: The magnetic force to a greater degree than heavier ions (based on Newton's second law of motion , F = ma ). The streams of magnetically sorted ions pass from the analyzer to the detector, which records the relative abundance of each ion type. This information is used to determine the chemical element composition of the original sample (i.e. that both sodium and chlorine are present in the sample) and
8611-415: The magnitude and orientation of the applied magnetic field. A common variation of the transmission quadrupole is the triple quadrupole mass spectrometer. The "triple quad" has three consecutive quadrupole stages, the first acting as a mass filter to transmit a particular incoming ion to the second quadrupole, a collision chamber, wherein that ion can be broken into fragments. The third quadrupole also acts as
8720-430: The mass resolving and mass determining capabilities of mass spectrometry is using it in tandem with chromatographic and other separation techniques. A common combination is gas chromatography-mass spectrometry (GC/MS or GC-MS). In this technique, a gas chromatograph is used to separate different compounds. This stream of separated compounds is fed online into the ion source, a metallic filament to which voltage
8829-850: The mass spectrometer. Sampling becomes easy as the samples don't need previous separation nor preparation. Some examples of ambient ionization techniques are Direct Analysis in Real Time (DART), DESI , SESI , LAESI , desorption atmospheric-pressure chemical ionization (DAPCI), Soft Ionization by Chemical Reaction in Transfer (SICRT) and desorption atmospheric pressure photoionization DAPPI among others. Others include glow discharge , field desorption (FD), fast atom bombardment (FAB), thermospray , desorption/ionization on silicon (DIOS), atmospheric pressure chemical ionization (APCI), secondary ion mass spectrometry (SIMS), spark ionization and thermal ionization (TIMS). Mass analyzers separate
8938-467: The mega-volt range, to accelerate negative ions into a type of tandem mass spectrometer. The METLIN Metabolite and Chemical Entity Database is the largest repository of experimental tandem mass spectrometry data acquired from standards. The tandem mass spectrometry data on over 930,000 molecular standards (as of January 2024) is provided to facilitate the identification of chemical entities from tandem mass spectrometry experiments. In addition to
9047-407: The most commonly used is the mass instability mode in which the RF potential is ramped so that the orbit of ions with a mass a > b are stable while ions with mass b become unstable and are ejected on the z -axis onto a detector. There are also non-destructive analysis methods. Ions may also be ejected by the resonance excitation method, whereby a supplemental oscillatory excitation voltage
9156-470: The name being a corruption of the French raisin de Corinthe ( Corinth grape). The names of the black and red currant, now more usually blackcurrant and redcurrant , two berries unrelated to grapes, are derived from this use. Some other fruits of similar appearance are also so named, for example, Australian currant, native currant, Indian currant. A sultana was originally a raisin made from Sultana grapes of Turkish origin (known as Thompson Seedless in
9265-574: The pomace). Anthocyanins tend to be the main polyphenolics in purple grapes, whereas flavan-3-ols (i.e. catechins ) are the more abundant class of polyphenols in white varieties. Total phenolic content is higher in purple varieties due almost entirely to anthocyanin density in purple grape skin compared to absence of anthocyanins in white grape skin. Phenolic content of grape skin varies with cultivar , soil composition, climate, geographic origin, and cultivation practices or exposure to diseases, such as fungal infections. Muscadine grapes contain
9374-482: The presence of cysteamine . Cranberries have A2-type proanthocyanidins (PACs) which may be important for the ability of PACs to bind to proteins, such as the adhesins present on E. coli fimbriae and were thought to inhibit bacterial infections, such as urinary tract infections (UTIs). Clinical trials have produced mixed results when asking the question to confirm that PACs, particularly from cranberries, were an alternative to antibiotic prophylaxis for UTIs: 1)
9483-550: The presence of (or an excess of) a nucleophile like phloroglucinol (reaction called phloroglucinolysis), benzyl mercaptan (reaction called thiolysis ), thioglycolic acid (reaction called thioglycolysis) or cysteamine . Flavan-3-ol compounds used with methanol produce short-chain procyanidin dimers , trimers , or tetramers which are more absorbable. These techniques are generally called depolymerisation and give information such as average degree of polymerisation or percentage of galloylation. These are SN1 reactions ,
9592-617: The production of gas phase ions suitable for resolution in the mass analyser or mass filter. Ionization occurs in the ion source . There are several ion sources available; each has advantages and disadvantages for particular applications. For example, electron ionization (EI) gives a high degree of fragmentation, yielding highly detailed mass spectra which when skilfully analysed can provide important information for structural elucidation/characterisation and facilitate identification of unknown compounds by comparison to mass spectral libraries obtained under identical operating conditions. However, EI
9701-498: The raisin or table market to produce white juice. Husrum , also known as verjuice , is a type of vinegar made from sour grapes in the Middle East. It is produced by crushing unripened grapes, collecting and salting the juice, simmering it to remove foam, and then storing it with a layer of olive oil to prevent contamination and oxidation. It is then used as an acidic ingredient in salads and stuffed vegetables. Unripened husrum grapes sent from Ashkelon to Egypt are mentioned in
9810-544: The reagent results in blue staining. It can also be used to titrate proanthocyanidins. Proanthocyanidins from field beans ( Vicia faba ) or barley have been estimated using the vanillin-HCl method , resulting in a red color of the test in the presence of catechins or proanthocyanidins. Proanthocyanidins can be titrated using the Procyanidolic Index (also called the Bates-Smith Assay ). It
9919-435: The recorded image currents. Orbitraps have a high mass accuracy, high sensitivity and a good dynamic range. Fourier-transform mass spectrometry (FTMS), or more precisely Fourier-transform ion cyclotron resonance MS, measures mass by detecting the image current produced by ions cyclotroning in the presence of a magnetic field. Instead of measuring the deflection of ions with a detector such as an electron multiplier ,
10028-452: The relatively cold climates of northeastern United States and southern Ontario . An offset to the improved eating quality of seedlessness is the loss of potential health benefits provided by the enriched phytochemical content of grape seeds (see Health claims , below). Grapes are eaten raw, dried (as raisins, currants and sultanas), or cooked. Also, depending on grape cultivar, grapes are used in winemaking. Grapes can be processed into
10137-461: The same species, Vitis vinifera , table and wine grapes have significant differences, brought about through selective breeding . Table grape cultivars tend to have large, seedless fruit (see below) with relatively thin skin. Wine grapes are smaller, usually seeded, and have relatively thick skins (a desirable characteristic in winemaking, since much of the aroma in wine comes from the skin). Wine grapes also tend to be very sweet: they are harvested at
10246-633: The same trapping field and ejected together simplifying detection that can be complicated with array configurations due to variations in detector alignment and machining of the arrays. As with the toroidal trap, linear traps and 3D quadrupole ion traps are the most commonly miniaturized mass analyzers due to their high sensitivity, tolerance for mTorr pressure, and capabilities for single analyzer tandem mass spectrometry (e.g. product ion scans). Orbitrap instruments are similar to Fourier-transform ion cyclotron resonance mass spectrometers (see text below). Ions are electrostatically trapped in an orbit around
10355-423: The sample is vaporized (turned into gas ) and ionized (transformed into electrically charged particles) into sodium (Na ) and chloride (Cl ) ions. Sodium atoms and ions are monoisotopic , with a mass of about 23 daltons (symbol: Da or older symbol: u). Chloride atoms and ions come in two stable isotopes with masses of approximately 35 u (at a natural abundance of about 75 percent) and approximately 37 u (at
10464-403: The second ionization energy of all except the most electropositive metals. The heating is achieved by a radio-frequency current passed through a coil surrounding the plasma. Photoionization can be used in experiments which seek to use mass spectrometry as a means of resolving chemical kinetics mechanisms and isomeric product branching. In such instances a high energy photon, either X-ray or uv,
10573-410: The signal. FTMS has the advantage of high sensitivity (since each ion is "counted" more than once) and much higher resolution and thus precision. Ion cyclotron resonance (ICR) is an older mass analysis technique similar to FTMS except that ions are detected with a traditional detector. Ions trapped in a Penning trap are excited by an RF electric field until they impact the wall of the trap, where
10682-436: The size of a trap is reduced, the shape of the electric field near the center of the trap, the region where the ions are trapped, forms a shape similar to that of a hyperbolic trap. A linear quadrupole ion trap is similar to a quadrupole ion trap, but it traps ions in a two dimensional quadrupole field, instead of a three-dimensional quadrupole field as in a 3D quadrupole ion trap. Thermo Fisher's LTQ ("linear trap quadrupole")
10791-499: The skin), and in the bark of Cinnamomum ( cinnamon ) and Pinus pinaster (pine bark; formerly known as Pinus maritima ), along with many other pine species. OPCs also can be found in blueberries , cranberries (notably procyanidin A2 ), aronia , hawthorn , rosehip , and sea buckthorn . Oligomeric proanthocyanidins can be extracted via Vaccinium pahalae from in vitro cell culture. The US Department of Agriculture maintains
10900-462: The subject molecule and as such result in little fragmentation. Examples include fast atom bombardment (FAB), chemical ionization (CI), atmospheric-pressure chemical ionization (APCI), atmospheric-pressure photoionization (APPI), electrospray ionization (ESI), desorption electrospray ionization (DESI), and matrix-assisted laser desorption/ionization (MALDI). Inductively coupled plasma (ICP) sources are used primarily for cation analysis of
11009-405: The systematic rupturing of bonds acts to remove the excess energy, restoring stability to the resulting ion). Resultant ions tend to have m/z lower than the molecular ion (other than in the case of proton transfer and not including isotope peaks). The most common example of hard ionization is electron ionization (EI). Soft ionization refers to the processes which impart little residual energy onto
11118-443: The time when their juice is approximately 24% sugar by weight. By comparison, commercially produced "100% grape juice", made from table grapes, is usually around 15% sugar by weight. Seedless cultivars now make up the overwhelming majority of table grape plantings. Because grapevines are vegetatively propagated by cuttings, the lack of seeds does not present a problem for reproduction. It is an issue for breeders, who must either use
11227-401: The value of an indicator quantity and thus provides data for calculating the abundances of each ion present. Some detectors also give spatial information, e.g., a multichannel plate. The following describes the operation of a spectrometer mass analyzer, which is of the sector type. (Other analyzer types are treated below.) Consider a sample of sodium chloride (table salt). In the ion source,
11336-415: The vine, and not corrupt. Mass spectrometry Mass spectrometry ( MS ) is an analytical technique that is used to measure the mass-to-charge ratio of ions . The results are presented as a mass spectrum , a plot of intensity as a function of the mass-to-charge ratio. Mass spectrometry is used in many different fields and is applied to pure samples as well as complex mixtures. A mass spectrum
11445-516: The wild across the continent and were a part of the diet of many Native Americans , but they were considered by early European colonists to be unsuitable for wine. In the 19th century, Ephraim Bull of Concord, Massachusetts , cultivated seeds from wild Vitis labrusca vines to create the Concord grape , which would become an important agricultural crop in the United States. Grapes are
11554-434: The world are dedicated to grapes. Approximately 71% of world grape production is used for wine, 27% as fresh fruit, and 2% as dried fruit . A portion of grape production goes to producing grape juice to be reconstituted for fruits canned "with no added sugar " and "100% natural". The area dedicated to vineyards is increasing by about 2% per year. There are no reliable statistics that break down grape production by variety. It
11663-482: The world, particularly for their role in winemaking . Other grape-derived products include various types of jam , juice , vinegar and oil. The Middle East is generally described as the homeland of grapes and the cultivation of this plant began there 6,000–8,000 years ago. Yeast , one of the earliest domesticated microorganisms , occurs naturally on the skins of grapes, leading to the discovery of alcoholic drinks such as wine. The earliest archeological evidence for
11772-400: Was used in early instruments when it was desired that the effects of adjustments be quickly observed. Once the instrument was properly adjusted, a photographic plate was inserted and exposed. The term mass spectroscope continued to be used even though the direct illumination of a phosphor screen was replaced by indirect measurements with an oscilloscope . The use of the term mass spectroscopy
11881-425: Was awarded to John Bennett Fenn for the development of electrospray ionization (ESI) and Koichi Tanaka for the development of soft laser desorption (SLD) and their application to the ionization of biological macromolecules , especially proteins . A mass spectrometer consists of three components: an ion source, a mass analyzer, and a detector. The ionizer converts a portion of the sample into ions. There
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