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Rooibos

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Rooibos
Scientific classification
Kingdom:
Plantae
(unranked):
Angiosperms
(unranked):
Eudicots
(unranked):
Rosids
Order:
Fabales
Family:
Fabaceae
Subfamily:
Faboideae
Tribe:
Crotalarieae
Genus:
Aspalathus
Species:
linearis
Binomial name
Aspalathus linearis
(N.L.Burm.) R.Dahlgr.
Flowers
Plant

Rooibos (Anglicized pronunciation: /ˈrɔɪbɒs/ ROY-bos; Afrikaans pronunciation: [rɔːibɔs], meaning "red bush"; scientific name Aspalathus linearis) is a broom-like member of the legume family of plants growing in South Africa's fynbos.

The generic name comes from the plant Calicotome villosa, aspalathos in Greek. This plant has very similar growth and flowers to the Rooibos plant. The specific name linearis comes from the plant's linear growing structure and needle-like leaves.

The leaves are used to make a herbal tea called Rooibos or bush tea (esp. Southern Africa). The product has been popular in Southern Africa for generations and is now consumed in many countries. It is sometimes spelled rooibosch in accordance with the old Dutch etymology.

Production

Green rooibos tea
Rooibos tea in a glass
A Rooibos-infused liqueur and Rooibos tea

Rooibos is usually grown in a small area in the region of the Western Cape province of South Africa.[1] Generally, the leaves are oxidized, a process often referred to as fermentation in accordance with tea processing terminology. This process produces the distinctive reddish-brown color of rooibos and enhances the flavor. Unoxidized "green" rooibos is also produced, but the more demanding production process for green rooibos (similar to the method by which green tea is produced) makes it more expensive than traditional rooibos. It carries a malty and slightly grassy flavour somewhat different from its red counterpart.

Use

In South Africa, it is common to prepare rooibos tea in the same manner as black tea and add milk and sugar to taste. Other methods include a slice of lemon and using honey instead of sugar to sweeten.

Several coffee shops in South Africa have recently begun to sell "red espresso", which is concentrated rooibos served and presented in the style of ordinary espresso. This has given rise to rooibos-based variations of coffee drinks such as red lattes and red cappuccinos. Iced tea made from rooibos has recently been introduced in South Africa, Australia, and in the United States. A variant of a London Fog, known as a Cape Town Fog, can also be made using Rooibos steeped in steamed milk with vanilla syrup.

Nutritional and health benefits

Rooibos is becoming more popular in Western countries, particularly among health-conscious consumers, due to its high level of antioxidants such as aspalathin[2] and nothofagin, its lack of caffeine, and its low tannin levels compared to fully oxidized black tea or unoxidized green tea leaves.[3] Rooibos also contains a number of phenolic compounds, including flavanols, flavones, flavanones, and dihydrochalcones.[4]

Rooibos is purported to assist with nervous tension, allergies and digestive problems.[5] Rooibos tea has been shown to inhibit in vitro activity of xanthine oxidase, but an in vivo study has not been conducted. Xanthine oxidase (XO) plays a role in conversion of purine to uric acid in humans and reducing the activity of XO could limit uric acid production, which would aid in treatment of gout. In in vitro tests only, for the specific concentration tested, the infusion was shown to be less than half as effective as allopurinol, which is the drug typically prescribed to inhibit XO activity in treating gout.[6]

Two flavonoids found in rooibos, quercetin and luteolin, have been known to have cancer fighting qualities.[7] Rooibos does not contain the antioxidant Epigallocatechin-3-gallate (EGCG) found in green tea.[8]

Traditional medicinal uses of rooibos in South Africa include alleviating infantile colic, allergies, asthma and dermatological problems.[9]

Scientific experiment

Human studies of rooibos are scarce in scientific literature.[10] Animal studies show that rooibos has potent antioxidant, immune-modulating and chemopreventive effects. A review found no documentation of adverse side effects of consuming rooibos tea.[10] A recent report identified a possible case of hepatotoxicity due to rooibos consumption, but concluded that further study was needed as the herbal tea may have been contaminated by another hepatotoxic compound, and or that the subject may have had a genetic predisposition to react negatively to one of the other bioactive properties found in the tea.[11] A study found that multiple compounds "abundant" in rooibos tea had mild estrogenic activity (like estrogen), although the exact concentration was not determined [12]

It is often claimed that "green" rooibos (see above) has a higher antioxidant capacity than fully oxidized rooibos. However, one study, using two different methods of measuring antioxidant activity, found conflicting data, with green rooibos showing more activity under one measure, and less activity using the other. The study also found conflicting data when comparing both forms of rooibos to black, green, and oolong tea, although it consistently found both forms to have less activity than green tea.[13]

In 2010, eleven poison dart frogs were raised at WWT Slimbridge by amphibian keepers in pint glasses of water, topped up with shop-bought Rooibos tea. Rooibos was used because it contains antioxidants with anti-fungal properties. This successfully protected the frogs against infection by chytridiomycosis.[14]

In 2011, researchers conducted a trial to test the effects of rooibos on various biological markers considered to be indicative of risk for cardiovascular disease and other degenerative diseases. A high intake of rooibos tea resulted in significant reductions in lipid peroxidation, LDL cholesterol, triglycerides, and an increase in HDL cholesterol levels compared with the control group. The researchers concluded that rooibos lowered risk factors.[15]

Grading

See also: Food grading

Rooibos grades are largely related to the percentage "needle" or leaf to stem content in the mix. A higher leaf content will result in a darker liquor, richer flavour and less "dusty" aftertaste. The high grade rooibos is exported and does not reach local markets, with major consumers being EU, particularly Germany, where it is used in creating flavoured blends for loose leaf tea markets. In development within South Africa are a small number of specialty tea companies producing similar blends.[citation needed]

History

Through the 17th and 18th centuries, European travellers and botanists visiting the Cederberg region in South Africa commented on the profusion of "good plants" for curative purposes. In 1772, Swedish naturalist Carl Thunberg noted that "the country people made tea" from a plant related to rooibos or redbush.

Traditionally, the local people would climb the mountains and cut the fine needle-like leaves from wild rooibos plants. They then rolled the bunches of leaves into hessian bags and brought them down the steep slopes on the backs of donkeys. The leaves were then chopped with axes and bruised with hammers, before being left to dry in the sun.

The Dutch settlers to the Cape developed rooibos as an alternative to black tea, an expensive commodity for the settlers who relied on supply ships from Europe.[16]

In 1904, Benjamin Ginsberg, a Russian/Jewish settler to the Cape, riding in the remote mountains, became fascinated with this wild tea. He ran a wide variety of experiments at Rondegat Farm, finally perfecting the curing of rooibos. He simulated the traditional Chinese method of making very fine Keemun, by fermenting the tea in barrels, covered in wet, hessian sacking that replicates the effects of bamboo baskets.[17]

In the 1930s, Ginsberg persuaded local doctor and Rhodes scholar Dr. Le Fras Nortier[18] to experiment with cultivation of the plant. Le Fras Nortier cultivated the first plants at Clanwilliam on the Klein Kliphuis farm. The tiny seeds were difficult to obtain, as they dispersed as soon as the pods cracked, and would not germinate without scarifying. Le Fras Nortier paid the local "volk", some of whom were his patients, to collect seeds. An aged Khoi woman came again and again, receiving a shilling for each matchbox filled with seed. She had found an unusual seed source: having chanced upon ants dragging seed, she followed them back to their nest and, on breaking it open, found a granary.[18] The attempts by Dr. le Fras Nortier were ultimately successful, which led Ginsberg to encourage local farmers to cultivate the plant in the hope that it would become a profitable venture. Klein Kliphuis became a tea farm, and within ten years the price of seeds soared to an astounding £80 a pound, the most expensive vegetable seed in the world. Today the seed is gathered by special sifting processes, and Klein Kliphuis is now a guest farm.[19]

Since then, rooibos has grown in popularity in South Africa, and has also gained considerable momentum in the worldwide market. A growing number of brand-name tea companies sell this tea, either by itself or as a component in an increasing variety of blends.

US trademark controversy

In 1994, Burke International registered the name "Rooibos" with the US Patent and Trademark Office, thus establishing a monopoly on the name in the United States at a time when it was virtually unknown there. When the plant later entered more widespread use, Burke demanded that companies either pay fees for use of the name, or cease its use. In 2005, the American Herbal Products Association and a number of import companies succeeded in defeating the trademark through petitions and lawsuits; after losing one of the cases, Burke surrendered the name to the public domain.[20]

If passed by the parliament of South Africa,[needs update] the Intellectual Property Laws Amendment Bill[21] of 2008 will provide for the protection and restriction on commercial use of the name Rooibos in that country. Similar legislation (protection of the names Champagne and Port for example) already exists in Europe. This is despite Rooibos South Africa's decision to contest the Burke trademark on the grounds that "rooibos" is a generic term, rather than claiming it as a geographic indication.[22]

Threat from climate change

The Rooibos plant is endemic to a small part of the western coast of the Western Cape province of South Africa, forming part of the fragile fynbos biome. It grows in a symbiotic relationship with local micro-organisms, and past attempts to grow Rooibos outside this area, in places as far afield as the United States, Australia and China, have all failed. Now, climate change may threaten the future survival of the plant and the R600-million Rooibos industry. Increasing temperatures and decreasing rainfall may result in the extinction of the Rooibos plant within the next century.[23]

See also

References

  1. ^ Standley, L (January 2001). "Influence of processing stages on antimutagenic and antioxidant potentials of rooibos tea". Journal of agricultural and food chemistry. 49 (1): 114–7. doi:10.1021/jf000802d. PMID 11170567. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  2. ^ Theunissen, Izelle (http://www.scienceinafrica.co.za/2005/march/rooibos.htm). "Rooibos the healthy tea". Science in Africa. {{cite web}}: Check date values in: |year= (help); External link in |year= (help); Missing or empty |url= (help); Unknown parameter |month= ignored (help)CS1 maint: year (link)
  3. ^ Morton, Julia F. (1983). "Rooibos tea,aspalathus linearis, a caffeineless, low-tannin beverage". Economic Botany. 37 (2): 164–73. doi:10.1007/BF02858780. JSTOR 4254477.
  4. ^ Krafczyk, Nicole; Woyand, Franziska; Glomb, Marcus A. (2009). "Structure-antioxidant relationship of flavonoids from fermented rooibos". Molecular Nutrition & Food Research. 53 (5): 635–42. doi:10.1002/mnfr.200800117. PMID 19156714.
  5. ^ Bramati, Lorenzo; Minoggio, Markus; Gardana, Claudio; Simonetti, Paolo; Mauri, Pierluigi; Pietta, Piergiorgio (2002). "Quantitative Characterization of Flavonoid Compounds in Rooibos Tea (Aspalathus linearis) by LC−UV/DAD". Journal of Agricultural and Food Chemistry. 50 (20): 5513–9. doi:10.1021/jf025697h. PMID 12236672.
  6. ^ Dew, Tristan P.; Day, Andrea J.; Morgan, Michael R. A. (2005). "Xanthine Oxidase Activity in Vitro: Effects of Food Extracts and Components". Journal of Agricultural and Food Chemistry. 53 (16): 6510–5. doi:10.1021/jf050716j. PMID 16076142.
  7. ^ Rubin, T. (February 2010). Better Nutrition. 72 (2): 48–9. {{cite journal}}: Missing or empty |title= (help)
  8. ^ Almajano, M. Pilar; Carbó, Rosa; Jiménez, J. Angel López; Gordon, Michael H. (2008). "Antioxidant and antimicrobial activities of tea infusions". Food Chemistry. 108: 55. doi:10.1016/j.foodchem.2007.10.040.
  9. ^ Joubert, E.; Gelderblom, W.C.A.; Louw, A.; De Beer, D. (2008). "South African herbal teas: Aspalathus linearis, Cyclopia spp. And Athrixia phylicoides—A review". Journal of Ethnopharmacology. 119 (3): 376–412. doi:10.1016/j.jep.2008.06.014. PMID 18621121.
  10. ^ a b McKay, Diane L.; Blumberg, Jeffrey B. (2007). "A review of the bioactivity of south African herbal teas: Rooibos (Aspalathus linearis) and honeybush (Cyclopia intermedia)". Phytotherapy Research. 21 (1): 1–16. doi:10.1002/ptr.1992. PMID 16927447.
  11. ^ Sinisalo, Marjatta; Enkovaara, Anna-Liisa; Kivistö, Kari T. (2010). "Possible hepatotoxic effect of rooibos tea: A case report". European Journal of Clinical Pharmacology. 66 (4): 427–8. doi:10.1007/s00228-009-0776-7. PMID 20072844.
  12. ^ Shimamura, Naomi; Miyase, Toshio; Umehara, Kaoru; Warashina, Tsutomu; Fujii, Satoshi (2006). "Phytoestrogens from Aspalathus linearis". Biological & pharmaceutical bulletin. 29 (6): 1271–4. doi:10.1248/bpb.29.1271. PMID 16755032.
  13. ^ Gadow, A.Von; Joubert, E.; Hansmann, C.F. (1997). "Comparison of the antioxidant activity of rooibos tea (Aspalathus linearis) with green, oolong and black tea". Food Chemistry. 60: 73. doi:10.1016/S0308-8146(96)00312-3.
  14. ^ "Exotic frogs reared in redbush tea in Gloucestershire". BBC News. 7 June 2010. Retrieved 12 September 2010.
  15. ^ Marnewick, Jeanine L.; Rautenbach, Fanie; Venter, Irma; Neethling, Henry; Blackhurst, Dee M.; Wolmarans, Petro; Macharia, Muiruri (2011). "Effects of rooibos (Aspalathus linearis) on oxidative stress and biochemical parameters in adults at risk for cardiovascular disease". Journal of Ethnopharmacology. 133 (1): 46–52. doi:10.1016/j.jep.2010.08.061. PMID 20833235.
  16. ^ "Rooibos History". South African Rooibos Council. Retrieved 19 August 2008.[unreliable source?]
  17. ^ History of Rooibos - Dragonfly Teas
  18. ^ a b Green, Lawrence (1949). In The Land of the Afternoon. Standard Press Ltd. pp. 52 to 54.
  19. ^ Klein Kliphuis Hotel website
  20. ^ Rooibos Trademark Abandoned American Herbal Products Association (AHPA) press release, 2005-06-28. Retrieved 2012-04-07.
  21. ^ "Intellectual Property Laws Amendment Bill: Draft, (G 31026, GeN 552)". South African Government Information. 5 May 2008. Retrieved 11 October 2008.
  22. ^ Trade Environment Database entry on "rooibos" name dispute in US
  23. ^ Climate change threatens rooibos, News24, 27 February 2012, retrieved 27 April 2013.

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