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Friday 17 June 2011

Asparagus(Plant)

Asparagus plant
Asparagus officinalis is a spring vegetable, a flowering perennial[1] plant species in the genus Asparagus. It was once classified in the lily family, like its Allium cousins, onions and garlic, but the Liliaceae have been split and the onion-like plants are now in the family Amaryllidaceae and asparagus in the Asparagaceae. Asparagus officinalis is native to most of Europe, northern Africa and western Asia,[2][3][4] and is widely cultivated as a vegetable crop.

Biology:
Asparagus is a herbaceous, perennial plant growing to 100–150 centimetres (39–59 in) tall, with stout stems with much-branched feathery foliage. The "leaves" are in fact needle-like cladodes (modified stems) in the axils of scale leaves; they are 6–32 millimetres (0.24–1.3 in) long and 1 millimetre (0.039 in) broad, and clustered 4–15 together. The root system is adventitious and the root type is fasciculated. The flowers are bell-shaped, greenish-white to yellowish, 4.5–6.5 millimetres (0.18–0.26 in) long, with six tepals partially fused together at the base; they are produced singly or in clusters of 2–3 in the junctions of the branchlets. It is usually dioecious, with male and female flowers on separate plants, but sometimes hermaphrodite flowers are found. The fruit is a small red berry 6–10 mm diameter, which is poisonous to humans.[5]
Plants native to the western coasts of Europe (from northern Spain north to Ireland, Great Britain, and northwest Germany) are treated as Asparagus officinalis subsp. prostratus (Dumort.) Corb., distinguished by its low-growing, often prostrate stems growing to only 30–70 centimetres (12–28 in) high, and shorter cladodes 2–18 millimetres (0.079–0.71 in) long.[2][6] It is treated as a distinct species, Asparagus prostratus Dumort, by some authors.[7][8] A remarkable adaptation is the edible asparagus, while in the Macaronesian Islands several species, (Asparagus umbellatus, Asparagus scoparius, etc.), are preserved the original form, a leafy vine; in the Mediterranean, the asparagus genus has evolved into thorny species.

History:
Asparagus has been used from early times as a vegetable and medicine, owing to its delicate flavour and diuretic properties. There is a recipe for cooking asparagus in the oldest surviving book of recipes, Apicius’s third century AD De re coquinaria, Book III. It was cultivated by the ancient Egyptians, Greeks and Romans, who ate it fresh when in season and dried the vegetable for use in winter. Asparagus is pictured on an Egyptian frieze dating to 3000 BC.
It lost its popularity in the Middle Ages, but returned to favour in the seventeenth century.[9] France's Louis XIV had special greenhouses built for growing it.

Uses:
1. Culinary
Only young asparagus shoots are commonly eaten: once the buds start to open ("ferning out"), the shoots quickly turn woody.[11]
Asparagus is low in calories [12] and is very low in sodium. It is a good source of vitamin B6, calcium, magnesium and zinc, and a very good source of dietary fiber, protein, vitamin A, vitamin C, vitamin E, vitamin K, thiamin, riboflavin, rutin, niacin, folic acid, iron, phosphorus, potassium, copper, manganese and selenium[13][14], as well as chromium, a trace mineral that enhances the ability of insulin to transport glucose from the bloodstream into cells[citation needed]. The amino acid asparagine gets its name from asparagus, the asparagus plant being rich in this compound.
The shoots are prepared and served in a number of ways around the world, typically as an appetizer[15] or vegetable side dish. In Asian-style cooking, asparagus is often stir-fried. Cantonese restaurants in the United States often serve asparagus stir-fried with chicken, shrimp, or beef, and also wrapped in bacon. Asparagus may also be quickly grilled over charcoal or hardwood embers. It is also used as an ingredient in some stews and soups. In the French style, it is often boiled or steamed and served with hollandaise sauce, melted butter or olive oil, Parmesan cheese or mayonnaise. Tall, narrow asparagus cooking pots allow the shoots to be steamed gently, their tips staying out of the water. In recent years, almost as a cycle dating back to early culinary habits, asparagus has regained its popularity eaten raw as a component of a salad.[16]
Asparagus can also be pickled and stored for several years. Some brands may label shoots prepared this way as "marinated".
The bottom portion of asparagus often contains sand and dirt, so thorough cleaning is generally advised in cooking it.
Green asparagus is eaten worldwide, though the availability of imports throughout the year has made it less of a delicacy than it once was.[6] However, in the UK, due to the short growing season and demand for local produce, asparagus commands a premium and the "asparagus season is a highlight of the foodie calendar."[17] In continental northern Europe, there is also a strong seasonal following for local white asparagus, nicknamed "white gold".

2. Medicinal
The second century physician Galen described asparagus as "cleansing and healing".
Nutrition studies have shown asparagus is a low-calorie source of folate and potassium. Its stalks are high in antioxidants. "Asparagus provides essential nutrients: six spears contain some 135 micrograms (μg) of folate, almost half the adult RDI (recommended daily intake), 20 milligrams of potassium," notes an article in Reader's Digest. Research suggests folate is key in taming homocysteine, a substance implicated in heart disease. Folate is also critical for pregnant women, since it protects against neural tube defects in babies. Several studies indicate getting plenty of potassium may reduce the loss of calcium from the body.
Particularly green asparagus is a good source of vitamin C. Vitamin C helps the body produce and maintain collagen, the major structural protein component of the body's connective tissues.
"Asparagus has long been recognized for its medicinal properties," wrote D. Onstad, author of Whole Foods Companion: A Guide for Adventurous Cooks, Curious Shoppers and Lovers of Natural Foods. "Asparagus contains substances that act as a diuretic, neutralize ammonia that makes us tired, and protect small blood vessels from rupturing. Its fiber content makes it a laxative, too."

Cultivation:
See also: List of asparagus diseases
Since asparagus often originates in maritime habitats, it thrives in soils that are too saline for normal weeds to grow. Thus, a little salt was traditionally used to suppress weeds in beds intended for asparagus; this has the disadvantage that the soil cannot be used for anything else. Some places are better for growing asparagus than others. The fertility of the soil is a large factor. "Crowns" are planted in winter, and the first shoots appear in spring; the first pickings or "thinnings" are known as sprue asparagus. Sprue has thin stems.[18]
White asparagus is cultivated by denying the plants light while they are being grown. Less bitter than the green variety, it is very popular in the Netherlands, France, Belgium and Germany, where 57,000 tonnes (61% of consumer demand) are produced annually.[19]
Purple asparagus differs from its green and white counterparts, having high sugar and low fibre levels. Purple asparagus was originally developed in Italy and commercialised under the variety name Violetto d'Albenga. Since then, breeding work has continued in countries such as the United States and New Zealand.[verification needed]
In northwestern Europe, the season for asparagus production is short, traditionally beginning on April 23 and ending on Midsummer Day.[20]
A new breed of "Early Season Asparagus" that can be harvested two months earlier than usual was announced by a UK grower in early 2011.[21] This variety does not need to lie dormant and blooms at 7 °C (45 °F) rather than the usual 9 °C (48 °F).

Companion planting:
Asparagus is a useful companion plant for tomatoes. The tomato plant repels the asparagus beetle, as do several other common companion plants of tomatoes. Meanwhile, asparagus may repel some harmful root nematodes that affect tomato plants.

Commercial production:
The top asparagus importers (2004) were the United States (92,405 tonnes), followed by the European Union (external trade) (18,565 tonnes), and Japan (17,148 tonnes).[23] China was the world's largest producer in 2005 (5,906,000 tonnes), followed by Peru (206,030 tonnes), and the United States (90,200 tonnes).[24][25] U.S. production was concentrated in California, Michigan and Washington.[24] The crop is significant enough in California's Sacramento-San Joaquin River Delta region that the city of Stockton holds a festival every year to celebrate it, as does the city of Hart, Michigan, complete with a parade and asparagus queen. The Vale of Evesham in Worcestershire is heralded as the largest producer within Northern Europe, celebrating like Stockton, with a week-long festival every year involving auctions of the best crop and locals dressing up as spears of asparagus as part of the British Asparagus Festival.[26] There is also a city festival in the Bavarian city of Nuremberg held for a week in April held in honour of the locally produced white asparagus i.e. Spargel. There is a competition to find the fastest spargel peeler in the region, which usually involves generous amounts of the local wines and beer being consumed to aid the spectators appreciative support.

Asparagus in Germany:
Spargel is the German name for asparagus. Most asparagus in Germany is white, as it is grown covered in soil (hilling) to prevent photosynthesis. This prevents the asparagus turning green and results in a taste a little sweeter and much more tender. It must be peeled before consumption. Spargel is generally harvested from late April to June, the season traditionally finishes on 24 June. Some green asparagus is available in Germany, but would most likely be called grüner Spargel.
Asparagus is very popular in the Netherlands, France, Belgium and Germany. In Germany it is known as "Königliches Gemüse" (Royal Vegetable). Germany produces 82,000 tons of asparagus a year; however, that is only enough to meet 61% of consumption. Many German cities hold festivals celebrating its harvest. Schwetzingen claims to be the "Asparagus Capital of the World" and holds an annual Spargelfest (asparagus festival) in which an Asparagus Queen is crowned. Situated in north-eastern Germany, also famous for its cultivation of asparagus, is the town of Beelitz in the Berlin-Brandenburg metropolitan area.
During Spargelsaison or Spargelzeit (asparagus season), asparagus is sold at many roadside stands and in open air markets: about half of all asparagus is bought in this way. It is also popular in restaurants, and fresh asparagus is advertised outside many restaurants during the season, during the season most restaurants have a Spargelkarte (asparagus menu) as well as their normal menu.

Vernacular names and etymology:
Asparagus officinalis is widely known simply as "asparagus", and may be confused with unrelated plant species also known as "asparagus", such as Ornithogalum pyrenaicum known as "Prussian asparagus" for its edible shoots.
The English word "asparagus" derives from classical Latin, but the plant was once known in English as sperage, from the Medieval Latin sparagus. This term itself derives from the Greek aspharagos or asparagos, and the Greek term originates from the Persian asparag, meaning "sprout" or "shoot". Asparagus was also corrupted in some places to "sparrow grass"; indeed, the Oxford English Dictionary quotes John Walker as having written in 1791 that "Sparrow-grass is so general that asparagus has an air of stiffness and pedantry". In Gloucestershire and Worcestershire, it is also known simply as "grass", and young plants too small to cut are called "pru"[citation needed]. Another known colloquial variation of the term, most common in parts of Texas, is "aspar grass" or "asper grass". In the Midwest United States and Appalachia, "spar grass" is a common colloquialism. Asparagus is commonly known in fruit retail circles as "Sparrows Guts", etymologically distinct from the old term "sparrow grass", thus showing convergent language evolution.[citation needed]
It is known in French and Dutch as asperge, in Italian as asparago (old Italian asparagio), in Portuguese as aspargo, in Spanish as espárrago, in German as Spargel, in Hungarian as spárga.
The Sanskrit name of Asparagus is shatavari and it has been historically used in India as a part of Ayurvedic medicines. In Kannada, it is known as ashadhi, majjigegadde or sipariberuballi.
In Thailand it is known as no mai farang (Thai: หน่อไม้ฝรั่ง), and in Vietnam măng tây which literally mean "European bamboo shoots" and "Western bamboo shoots", respectively. The green asparagus is normally used in Thai cuisine.

Urine effect:
The effect of eating asparagus on the eater's urine has long been observed:
"[Asparagus] cause a filthy and disagreeable smell in the urine, as everybody knows." (Treatise of All Sorts of Foods, Louis Lemery, 1702).
"asparagus... affects the urine with a foetid smell (especially if cut when they are white) and therefore have been suspected by some physicians as not friendly to the kidneys; when they are older, and begin to ramify, they lose this quality; but then they are not so agreeable" ("An Essay Concerning the Nature of Aliments," John Arbuthnot, 1735)[29]
Asparagus "...transforms my chamber-pot into a flask of perfume." Marcel Proust (1871–1922) [30]
There is debate about whether all (or only some) people produce the smell, and whether all (or only some) people identify the smell. It was originally thought this was because some of the population digested asparagus differently from others, so some people excreted odorous urine after eating asparagus, and others did not. In the 1980s three studies from France,[31] China and Israel published results showing that producing odorous urine from asparagus was a universal human characteristic (if not one that pertains to human beings essentially). The Israeli study found that from their 307 subjects all of those who could smell 'asparagus urine' could detect it in the urine of anyone who had eaten asparagus, even if the person who produced it could not detect it himself.[32] However, a 2010 study[33] found variations in both production of odorous urine and the ability to detect the odour, but that these were not tightly related. It is believed most people produce the odorous compounds after eating asparagus, but only about 22% of the population have the autosomal genes required to smell them.
Chemistry:
Certain compounds in asparagus are metabolized, giving urine a distinctive smell due to various sulfur-containing degradation products, including various thiols, thioesters, and ammonia.[37]
The volatile organic compounds responsible for the smell are identified as:[38][39]
Subjectively, the first two are the most pungent, while the last two (sulfur-oxidized) give a sweet aroma. A mixture of these compounds form a "reconstituted asparagus urine" odor. This was first investigated in 1891 by Marceli Nencki, who attributed the smell to methanethiol.[40] These compounds originate in the asparagus as asparagusic acid and its derivatives, as these are the only sulfur-containing compounds unique to asparagus. As these are more present in young asparagus, this accords with the observation that the smell is more pronounced after eating young asparagus. The biological mechanism for the production of these compounds is less clear.[citation needed]
The onset of the asparagus urine smell is remarkably rapid. It has been estimated to start 15 to 30 minutes after ingestion.

See also:
References:
  1. ^ Grubben, G.J.H.; Denton, O.A., eds (2004). Plant Resources of Tropical Africa 2. Vegetables. PROTA Foundation, Wageningen; Backhuys, Leiden; CTA, Wageningen. 
  2. ^ a b "Asparagus officinalis". Flora Europaea. Royal Botanic Garden Edinburgh. http://rbg-web2.rbge.org.uk/cgi-bin/nph-readbtree.pl/feout?FAMILY_XREF=&GENUS_XREF=Asparagus&SPECIES_XREF=officinalis&TAXON_NAME_XREF=&RANK=. Retrieved 2010-05-19. 
  3. ^ "Asparagus officinalis". Euro+Med Plantbase Project. Botanic Garden and Botanical Museum Berlin-Dahlem. http://ww2.bgbm.org/_EuroPlusMed/PTaxonDetail.asp?NameId=38660&PTRefFk=500000. Retrieved 2010-05-19. 
  4. ^ USDA, ARS, National Genetic Resources Program. "Asparagus officinalis". Germplasm Resources Information Network. Beltsville, Maryland: National Germplasm Resources Laboratory. http://www.ars-grin.gov/cgi-bin/npgs/html/taxon.pl?300050. Retrieved 2010-05-19. 
  5. ^ http://www.gardengrow.co.nz/plant/Asparagus
  6. ^ a b Blamey, M. & Grey-Wilson, C. (1989). Flora of Britain and Northern Europe. ISBN 0-340-40170-2
  7. ^ Stace, Clive; van der Meijden, Ruud (ed.); de Kort, Ingrid (ed.). "Asparagus prostratus (Asparagus, Wild)". Interactive Flora of NW Europe. ETI BioInformatics. http://ip30.eti.uva.nl/BIS/flora.php?selected=beschrijving&menuentry=soorten&id=4839. Retrieved 2010-05-19. 
  8. ^ USDA, ARS, National Genetic Resources Program. "Asparagus prostratus". Germplasm Resources Information Network. Beltsville, Maryland: National Germplasm Resources Laboratory. http://www.ars-grin.gov/cgi-bin/npgs/html/taxon.pl?5538. Retrieved 2010-05-19. 
  9. ^ Vaughan, John Griffith; Geissler, Catherine Alison; Nicholson, Barbara (1997). The New Oxford Book of Food Plants. Oxford University Press. 
  10. ^ Zeldes, Leah A. (2010-04-21). "Eat this! Asparagus, the vegetable of kings". Dining Chicago. Chicago's Restaurant & Entertainment Guide, Inc.. http://www.diningchicago.com/blog/2010/04/21/eat-this-asparagus-the-vegetable-of-kings/. Retrieved 2010-05-22. 
  11. ^ "Growing Asparagus in the Home Garden". Section on harvesting, page 2. Purdue University Cooperative Extension Service. Retrieved 2011-06-06
  12. ^ Asparagus nutritional information
  13. ^ NutritionData.com entry on asparagus (referenced from USDA data)
  14. ^ USDA Agricultural Research Service Data section 11 (pg 61)
  15. ^ Asparagus appetizer recipe
  16. ^ Salad Recipe
  17. ^ British Asparagus
  18. ^ "BBC – Food – Glossary – 'S'". BBC Online. http://www.bbc.co.uk/food/glossary/s.shtml?sprue_asparagus. Retrieved 2007-06-08. 
  19. ^ Molly Spence. "Asparagus: The King of Vegetables" (DOC). German Agricultural Marketing Board. Archived from the original on 2007-10-13. http://web.archive.org/web/20071013032017/http://www.germanfoods.org/consumer/documents/WhiteAsparagusPressRelease.doc. Retrieved 2007-02-26. 
  20. ^ Oxford Times: "Time to glory in asparagus again".
  21. ^ "New breed of early asparagus hits the shelves". The Daily Telegraph. March 19, 2011. http://www.telegraph.co.uk/foodanddrink/8392483/New-breed-of-early-asparagus-hits-the-shelves.html. Retrieved March 20, 2011. 
  22. ^ http://www.ibiblio.org/pfaf/cgi-bin/arr_html?Asparagus+officinalis
  23. ^ According to Global Trade Atlas and U.S. Census Bureau statistics
  24. ^ a b USDA (January 2006). Vegetables 2005 Summary. National Agricultural Statistics Service. 
  25. ^ "Food and Agriculture Organisation Statistics (FAOSTAT)". Archived from the original on 2007-11-07. http://web.archive.org/web/20071107164115/http://faostat.fao.org/site/336/DesktopDefault.aspx?PageID=336. Retrieved 2007-11-11. 
  26. ^ "British Aparagus Festival". http://www.british-asparagus.co.uk/asparagus_festival.php#cotswolds. 
  27. ^ "Official internet portal of the City of Nuremberg". http://www.nuernberg.de/internet/portal_e/index.html. 
  28. ^ McGee, Harold (2004). "6". McGee on Food and Cooking. Hodder and Stoughton. pp. 315. ISBN 0340831499. 
  29. ^ Arbuthnot J (1735). An Essay Concerning the Nature of Aliments 3rd ed.. London: J. Tonson. pp. 64261–262. 
  30. ^ From the French "[...] changer mon pot de chambre en un vase de parfum," Du côté de chez Swann, Gallimard, 1988.
  31. ^ C. RICHER1, N. DECKER2, J. BELIN3, J. L. IMBS2, J. L. MONTASTRUC3 & J. F. GIUDICELLI (May 1989). "Odorous urine in man after asparagus". Br J. Clin. Pharmac. PMC 1379934. PMID 2757887. 
  32. ^ S. C. MITCHELL (May 1989). "Asparagus and malodorous urine". Br J. Clin. Pharmac. PMC 1379935. PMID 2757888. 
  33. ^ Pelchat, M. L.; Bykowski, C., Duke, F. F., Reed, D. R. (NaN undefined NaN). "Excretion and Perception of a Characteristic Odor in Urine after Asparagus Ingestion: a Psychophysical and Genetic Study". Chemical Senses 36 (1): 9–17. doi:10.1093/chemse/bjq081. http://chemse.oxfordjournals.org/content/early/2010/09/27/chemse.bjq081.abstract. 
  34. ^ "The scientific chef: asparagus pee". The Guardian. September 23, 2005. http://www.guardian.co.uk/food/story/0,,1576765,00.html. Retrieved 2007-04-21. 
  35. ^ Hannah Holmes. "Why Asparagus Makes Your Pee Stink". Discover.com. http://www.discovery.com/area/skinnyon/skinnyon970115/skinny1.html. 
  36. ^ Lison M, Blondheim SH, Melmed RN. (1980). "A polymorphism of the ability to smell urinary metabolites of asparagus". Br Med J 281 (6256): 1676. doi:10.1136/bmj.281.6256.1676. PMC 1715705. PMID 7448566. 
  37. ^ White RH. (1975). "Occurrence of S-methyl thioesters in urines of humans after they have eaten asparagus". Science 189 (4205): 810–11. doi:10.1126/science.1162354. PMID 1162354. http://www.sciencemag.org/cgi/pmidlookup?view=long&pmid=1162354. 
  38. ^ Waring RH, Mitchell SC and Fenwick GR (1987). "The chemical nature of the urinary odour produced by man after asparagus ingestion". Xenobiotica 17 (11): 1363–1371. doi:10.3109/00498258709047166. PMID 3433805. 
  39. ^ Mitchell, S.C. (2001). "Food idiosyncrasies: beetroot and asparagus". Drug Metabolism and Disposition. 29 (4): 539–543.
  40. ^ Nencki, Marceli (1891). "Ueber das vorkommen von methylmercaptan im menschlichen harn nach spargelgenuss". Arch Exp Path Pharmak 28: 206–209. doi:10.1007/BF01824333. 
  41. ^ Somer, E. (August 14, 2000). "Eau D'Asparagus". WebMD. http://www.webmd.com/content/article/43/1671_51089. Retrieved 2006-08-31. 
  42. ^ Research completed and verified by Dr. R. McLellan from the University of Waterloo.
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