Methoxypyrazines

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Chemical structure of isopropyl methoxy pyrazine (IPMP) IPMP.png
Chemical structure of isopropyl methoxy pyrazine (IPMP)

Methoxypyrazines are a class of chemical compounds that produce odors. The odors tend to be undesirable, as in the case of certain wines, [1] or as in the case of the Asian Lady Beetle 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). [1]

Isopropyl methoxy pyrazine chemical compound

Isopropyl methoxy pyrazine (IPMP) is a methoxypyrazine, a class of chemical compounds that produce odors. The odor is rather undesirable and is produced by the Asian lady beetle or by the actinomycete Streptomyces sp. It can be detected by human taste at concentrations of as low as 2 nanograms per litre.

Contents

Examples of methoxypyrazines in wine grapes

Cabernet Sauvignon has high levels of methoxypyrazines. [2] [3] 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. [4]

Cabernet Sauvignon red-wine variety of grape

Cabernet Sauvignon is one of the world's most widely recognized red wine grape varieties. It is grown in nearly every major wine producing country among a diverse spectrum of climates from Canada's Okanagan Valley to Lebanon's Beqaa Valley. Cabernet Sauvignon became internationally recognized through its prominence in Bordeaux wines where it is often blended with Merlot and Cabernet Franc. From France, the grape spread across Europe and to the New World where it found new homes in places like California's Santa Cruz Mountains, Paso Robles, Napa Valley, New Zealand's Hawkes Bay, Australia's Margaret River and Coonawarra regions, and Chile's Maipo Valley and Colchagua. For most of the 20th century, it was the world's most widely planted premium red wine grape until it was surpassed by Merlot in the 1990s. However, by 2015, Cabernet Sauvignon had once again become the most widely planted wine grape, with a total of 341000ha under vine worldwide.

Sauvignon blanc green-skinned grape variety that originates from the Bordeaux region of France

Sauvignon blanc is a green-skinned grape variety that originates from the Bordeaux region of France. The grape most likely gets its name from the French words sauvage ("wild") and blanc ("white") due to its early origins as an indigenous grape in South West France. It is possibly a descendant of Savagnin. Sauvignon blanc is planted in many of the world's wine regions, producing a crisp, dry, and refreshing white varietal wine. The grape is also a component of the famous dessert wines from Sauternes and Barsac. Sauvignon blanc is widely cultivated in France, Chile, Romania, Canada, Australia, New Zealand, South Africa, the states of Washington and California in the US. Some New World Sauvignon blancs, particularly from California, may also be called "Fumé Blanc", a marketing term coined by Robert Mondavi in reference to Pouilly-Fumé.

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Cabernet Franc grapevine that yields black grapes used for wine

Cabernet Franc is one of the major black grape varieties worldwide. It is principally grown for blending with Cabernet Sauvignon and Merlot in the Bordeaux style, but can also be vinified alone, as in the Loire's Chinon. In addition to being used in blends and produced as a varietal in Canada and the United States, it is sometimes made into ice wine in those regions.

Chenin blanc varietal

Chenin blanc is a White wine grape variety from the Loire Valley of France. Its high acidity means it can be used to make everything from sparkling wines to well-balanced dessert wines, although it can produce very bland, neutral wines if the vine's natural vigor is not controlled. Outside the Loire it is found in most of the New World wine regions; it is the most widely planted variety in South Africa, where it is also known as Steen. The grape may have been one of the first to be grown in South Africa by Jan van Riebeeck in 1655, or it may have come to that country with Huguenots fleeing France after the revocation of the Edict of Nantes in 1685. Chenin blanc was often misidentified in Australia as well, so tracing its early history in the country is not easy. It may have been introduced in James Busby's collection of 1832, but C. Waterhouse was growing Steen at Highercombe in Houghton, South Australia, by 1862.

Furmint varietal

Furmint is a white Hungarian wine grape variety that is most noted widely grown in the Tokaj-Hegyalja wine region where it is used to produce single-varietal dry wines as well as being the principal grape in the better known Tokaji dessert wines. It is also grown in the tiny Hungarian wine region of Somló. Furmint plays a similar role in the Slovakian wine region of Tokaj. It is also grown in Austria where it is known as Mosler. Smaller plantings are found in Slovenia where it is known as Šipon. The grape is also planted in Croatia where it is known as Moslavac. It is also found in Romania and in former republics of the Soviet Union. Furmint is a late ripening variety. For dry wines the harvest starts usually in September, however sweet wine specific harvest can start in the second half of October or even later, and is often affected by Botrytis.

Sémillon wine making grape

Sémillon is a golden-skinned grape used to make dry and sweet white wines, mostly in France and Australia. Its thin skin and susceptibility to botrytis make it dominate the sweet wine region Sauternes AOC and Barsac AOC.

McLaren Vale Australian Geographical indication

McLaren Vale is a wine region in the Australian state of South Australia located in the Adelaide metropolitan area and centred on the town of McLaren Vale about 38 kilometres (24 mi) south of the Adelaide city centre. It is internationally renowned for the wines it produces and included within the Great Wine Capitals of the World. The region was named after either David McLaren, the Colonial Manager of the South Australia Company or John McLaren (unrelated) who surveyed the area in 1839. Among the first settlers to the region in late 1839, were two English farmers from Devon, William Colton and Charles Thomas Hewett. William Colton established the Daringa Farm and Charles Thomas Hewett established Oxenberry Farm. Both men would be prominent in the early days of McLaren Vale. Although initially the region's main economic activity was the growing of cereal crops, John Reynell and Thomas Hardy planted grape vines in 1838 and the present-day Seaview and Hardy wineries were in operation as early as 1850. Grapes were first planted in the region in 1838 and some vines more than 100 years old are still producing. Today there are more than 88 cellar doors in McLaren Vale. The majority are small family-run operations and boutique wineries.

Sancerre (wine)

Sancerre is a French wine Appellation d'origine contrôlée or AOC for wine produced in the area of Sancerre in the eastern part of the Loire valley, southeast of Orléans. Almost all of the appellation lies on the left bank of the Loire, opposite Pouilly-Fumé. It is well regarded for and primarily associated with Sauvignon blanc. Some Pinot noir is also grown, accounting for around 20% of the region's production, making mostly light red wines under the designation of Sancerre Rouge. A rosé style from Pinot noir is also produced in a style similar to Beaujolais.

A wine fault or defect is an unpleasant characteristic of a wine often resulting from poor winemaking practices or storage conditions, and leading to wine spoilage. Many of the compounds that cause wine faults are already naturally present in wine but at insufficient concentrations to be of issue. In fact, depending on perception, these concentrations may impart positive characters to the wine. However, when the concentration of these compounds greatly exceeds the sensory threshold, they replace or obscure the flavors and aromas that the wine should be expressing. Ultimately the quality of the wine is reduced, making it less appealing and sometimes undrinkable.

Sauvignon vert is a white wine grape of the species Vitis vinifera prevalent in the Italian region of Friuli. It is widely planted in Chile where it was historically mistaken for Sauvignon blanc. The grape is distinct from the California planting of Muscadelle which is also called Sauvignon vert.

Victorian wine

Victorian wine is wine made in the Australian state of Victoria. With over 600 wineries, Victoria has more wine producers than any other Australian wine-producing state but ranks third in overall wine production due to the lack of a mass bulk wine-producing area like South Australia's Riverland and New South Wales's Riverina. Viticulture has existed in Victoria since the 19th century and experienced a high point in the 1890s when the region produced more than half of all wine produced in Australia. The phylloxera epidemic that soon followed took a hard toll on the Victoria wine industry which did not fully recover till the 1950s.

Friuli-Venezia Giulia wine wine

Friuli-Venezia Giulia wine is wine made in the northeastern Italian region of Friuli-Venezia Giulia. Once part of the Venetian Republic and with sections under the influence of the Austro-Hungarian Empire for some time, the wines of the region have noticeable Slavic and Germanic influences. There are 11 Denominazione di origine controllata (DOC) and 3 Denominazione di Origine Controllata e Garantita (DOCG) in the Friuli-Venezia Giulia area. The region has 3 Indicazione Geografica Tipica (IGT) designations Alto Livenza, delle Venezie and Venezia Giulia. Nearly 62% of the wine produced in the region falls under a DOC designation. The area is known predominantly for its white wines which are considered some of the best examples of Italian wine in that style. Along with the Veneto and Trentino-Alto Adige/Südtirol, the Friuli-Venezia Giulia forms the Tre Venezie wine region which ranks with Tuscany and Piedmont as Italy's world class wine regions.

Aroma of wine

The aromas of wine are more diverse than its flavors. The human tongue is limited to the primary tastes perceived by taste receptors on the tongue-sourness, bitterness, saltiness, sweetness and savoriness. The wide array of fruit, earthy, leathery, floral, herbal, mineral, and woodsy flavor present in wine are derived from aroma notes sensed by the olfactory bulb. In wine tasting, wine is sometimes smelled before being drunk in order to identify some components of the wine that may be present. Different terms are used to describe what is being smelled. The most basic term is aroma which generally refers to a "pleasant" smell as opposed to odor which refers to an unpleasant smell or possible wine fault. The term aroma may be further distinguished from bouquet which generally refers to the smells that arise from the chemical reactions of fermentation and aging of the wine.

Incrocio Manzoni varietal

Incrocio Manzoni or Manzoni grapes is a family of grape varieties named after Professor Luigi Manzoni (1888-1968) of Italy's oldest school of oenology located in Conegliano, in the Veneto region. Manzoni created the new grape varieties by selecting, crossing and grafting vines from various vineyards during the 1920s and 1930s. The family includes both white and red grape varieties. Although most Manzonis are grown in northeastern Italy, they are mainly grown in the Piave area of Province of Treviso and are only now starting to be sold commercially in Europe and the United States.

Merlot blanc is a white French wine grape variety that came from a natural crossing of the Bordeaux wine grape Merlot and the Cognac grape Folle blanche. The grape is distinct from Merlot gris which is a pink-skinned color mutation of the red wine grape Merlot and is sometimes used in vin gris and rosé wines. Plantings of Merlot blanc were first discovered in 1891 but cuttings of the vine have not been widely propagated and the variety is very rare. It is not used to make the sweet White Zinfandel-style wine White Merlot that is made by some California wine producers. Those wines are made from a saignee of red Merlot wine.

Cabernet blanc is a white German and Swiss wine grape variety that is a crossing of the French wine grape Cabernet Sauvignon and an unknown hybrid grape variety. The grape was bred by Swiss grape breeder Valentin Blattner in 1991. Cabernet blanc has strong resistance to most grape disease including botrytis bunch rot, downy and powdery mildew and tends to produce loose clusters of small, thick-skinned grape berries which can hang on the vine late into the harvest season to produce dessert wines. Today the grape is found primarily in the Palatinate wine region of Germany with some experimental plantings in the Netherlands.

Cygne blanc is a white Australian wine grape variety that is a seedling of Cabernet Sauvignon that was discovered in 1989 in Western Australia. Unlike Cabernet blanc, which was a crossing of Cabernet Sauvignon and Resistenzpartner, and Shalistin which is a white-berried color mutation of Cabernet Sauvignon, Cygne blanc is a selfling that sprang from a seed of a Cabernet Sauvignon berry that fell on the ground and took root.

3-Isobutyl-2-methoxypyrazine chemical compound

3-Isobutyl-2-methoxypyrazine is a methoxypyrazine that is very similar to isopropyl methoxy pyrazine except that the alkyl side-group contains an isobutyl group attached to the carbon alpha to the methoxy sidegroup instead of an isopropyl side-group at that same carbon position.

Baratuciat

Baratuciat is a white Italian wine grape variety that is grown in the Piedmont wine region of northwest Italy. For most of its history, Baratuciat was used mainly as a table grape with some limited use for wine production with sweet late-harvest dessert wines. On June 23, 2008, the grape was officially added to the Italian registry of wine grape varieties.

References

  1. 1 2 Trace flavour components of grapes
  2. winepros.com.au Oxford Companion to Wine methoxypyrazines Archived 2012-02-29 at the Wayback Machine .
  3. Oz Clarke Encyclopedia of Grapes pg 223 Harcourt Books 2001 ISBN   0-15-100714-4
  4. 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.