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A tannin (also known as vegetable tannin, natural organic tannins or sometimes tannoid, i.e. a type of biomolecule, as opposed to modern synthetic tannin) is an astringent, bitter plant polyphenolic compound that binds to and precipitates proteins and various other organic compounds including amino acids and alkaloids.

The term tannin (from tanna, an Old High German word for oak or fir tree, as in Tannenbaum) refers to the use of wood tannins from oak in tanning animal hides into leather; hence the words "tan" and "tanning" for the treatment of leather. However, the term "tannin" by extension is widely applied to any large polyphenolic compound containing sufficient hydroxyls and other suitable groups (such as carboxyls) to form strong complexes with proteins and other macromolecules.

The tannin compounds are widely distributed in many species of plants, where they play a role in protection from predation, and perhaps also as pesticides, and in plant growth regulation.^[1] The astringency from the tannins is what causes the dry and puckery feeling in the mouth following the consumption of unripened fruit or red wine.^[2] Likewise, the destruction or modification of tannins with time plays an important role in the ripening of fruit and the aging of wine.

Tannins have molecular weights ranging from 500 to over 3,000^[3] (gallic acid esters) and up to 20,000 (proanthocyanidins). Tannins are incompatible with alkalis, gelatin, heavy metals, iron, limewater, metallic salts, strong oxidizing agents and zinc sulfate, since they form complexes and precipitate in aqueous solution.

History

Austrian chemist Heinrich Hlasiwetz (1825–1875) worked on tannins. The biochemist Maximilian Nierenstein studied the natural tannins in 1934. The chemist Karl Johann Freudenberg studied them in the 1920s.

Occurrence

Tannins are distributed in species throughout the plant kingdom. They are commonly found in both gymnosperms as well as angiosperms. Mole^[4] (1993) studied the distribution of tannin in 180 families of dicotyledons and 44 families of monocotyledons (Cronquist). Most families of dicot contain tannin-free species (tested by their ability to precipitate proteins).

The best known families of which all species tested contain tannin are: Aceraceae, Actinidiaceae, Anacardiaceae, Bixaceae, Burseraceae, Combretaceae, Dipterocarpaceae, Ericaceae, Grossulariaceae, Myricaceae for dicot and Najadaceae and Typhaceae in Monocot. To the family of the oak, Fagaceae, 73% of the species tested (N = 22) contain tannin. For those of acacias, Mimosaceae, only 39% of the species tested (N = 28) contain tannin, among Solanaceae rate drops to 6% and 4% for the Asteraceae. Some families like the Boraginaceae, Cucurbitaceae, Papaveraceae contain no tannin-rich species.

Tannins are mainly physically located in the vacuoles or surface wax of plants. These storage sites keep tannins active against plant predators, but also keep some tannins from affecting plant metabolism while the plant tissue is alive; it is only after cell breakdown and death that the tannins are active in metabolic effects. Tannins are classified as ergastic substances, i.e., non-protoplasm materials found in cells.

Tannins are found in leaf, bud, seed, root, and stem tissues. An example of the location of the tannins in stem tissue is that they are often found in the growth areas of trees, such as the secondary phloem and xylem and the layer between the cortex and epidermis. Tannins may help regulate the growth of these tissues.

There may be a loss in the bio-availability of still other tannins in plants due to birds, pests, and other pathogens.^[5]

The most abundant polyphenols are the condensed tannins, found in virtually all families of plants, and comprising up to 50% of the dry weight of leaves.

Cellular localization

Tannins, by definition, precipitate proteins. In this condition, they must be stored in organelles able to withstand the protein precipitation process. Idioblasts are isolated plant cells which differ from neighboring tissues and contain non-living substances. They have various functions such as storage of reserves, excretory materials, pigments, and minerals. They could contain oil, latex, gum, resin or pigments etc. They also can contain tannins. In Japanese persimmon (Diospyros kaki) fruits, tannin is accumulated in the vacuole of tannin cells, which are idioblasts of parenchyma cells in the flesh.^[6]

Presence in soils

The convergent evolution of tannin-rich plant communities has occurred on nutrient-poor acidic soils throughout the world. Tannins were once believed to function as anti-herbivore defenses, but more and more ecologists now recognize them as important controllers of decomposition and nitrogen cycling processes. As concern grows about global warming, there is great interest to better understand the role of polyphenols as regulators of carbon cycling, in particular in northern boreal forests.

Leaf litter and other decaying parts of a kauri (Agathis australis), a tree species found in New Zealand, decompose much more slowly than those of most other species. Besides its acidity, the plant also bears substances such as waxes and phenols, most notably tannins,^[7] that are harmful to microorganisms.

Presence in water and wood

The leaching of highly water soluble tannins from decaying vegetation and leaves along a stream may produce what is known as a blackwater river. Water flowing out of bogs has a characteristic brown color from dissolved peat tannins. The presence of tannins (or humic acid) in well water can make it smell bad or taste bitter, but not be unsafe to drink.^[8]

Tannins leaching from an unprepared driftwood decoration in an aquarium can cause pH lowering and coloring of the water to a tea-like tinge. A way to avoid this is to boil the wood in water several times (which will also darken and waterlog the wood, i.e., make it sink), discarding the water each time. Using peat as an aquarium substrate can have the same effect.

Many hours of boiling the driftwood may need to be followed by many weeks or months of constant soaking and many water changes before the water will stay clear. Adding baking soda to the water to raise its pH level will accelerate the process of leaching, as the more alkaline solution can draw out tannic acid from the wood faster than the pH-neutral water.^[9]

Softwoods, while in general much lower in tannins than hardwoods,^[10] are usually not recommended for use in an aquarium^[11] so using a hardwood with a very light color, indicating a low tannin content, can be an easy way to avoid tannins. Tannic acid is brown in color, so in general white woods have a low tannin content. Woods with a lot of yellow, red, or brown coloration to them (like southern yellow pine, cedar, redwood, red oak, etc.) tend to contain a lot of tannin.^[12]

Extraction

There is no single protocol for extracting tannins from all plant material. The procedures used for tannins are widely variable.^[13] It may be that acetone in the extraction solvent increases the total yield by inhibiting interactions between tannins and proteins during extraction^[13] or even by breaking hydrogen bonds between tannin-protein complexes.^[14]

Tests for tannins

gold beater skin test

When gold beater skin or ox skin is dipped in HCl and treated with 1% FeSO₄ solution. After washing with water, it gives a blue black colour.

KOH test

1 cm³ of freshly prepared 10% KOH is added to 1 cm³ of the extract. A dirty white precipitate indicates the presence of tannins.

Ferric chloride (FeCl₃) test

It is rather a test for phenolics in general. Powdered plant leaves of the test plant (1.0 g) are weighed into a beaker and 10 ml of distilled water are added. The mixture is boiled for five minutes. Two drops of 5% FeCl₃ are then added. Production of a greenish precipitate was an indication of the presence of tannins.^[15] Alternatively, a portion of the water extract is diluted with distilled water in a ratio of 1:4 and few drops of 10% ferric chloride solution is added. A blue or green colour indicates the presence of tannins (Evans, 1989).^[16]

Classes of tannins

There are three major classes of tannins:^[17]

Base Unit:	Gallic acid	Flavone	Phloroglucinol
Class/Polymer:	Hydrolyzable tannins	Non-Hydrolyzable or condensed tannins	Phlorotannins
Sources	Plants	Plants	Brown algae

Pseudo tannins

Pseudo tannins are low molecular weight compounds associated with other compounds. They do not answer gold beater skin test unlike hydrolysable and condensed tannins.^[17] They are found in tea or coffee^[18] or in:^[19]

Gallic acid: rhubarb
flavan-3-ols (Catechins): Acacia, catechu, cocoa, guarana
Chlorogenic acid: Nux-vomica, coffee, mate
Ipecacuanhic acid: Carapichea ipecacuanha

Nutrition

Tannins have traditionally been considered antinutritional but it is now known that their beneficial or antinutritional properties depend upon their chemical structure and dosage. The new technologies used to analyze molecular and chemical structures have shown that a division into condensed and hydrolyzable tannins is far too simplistic.^[20] Recent studies have demonstrated that products containing chestnut tannins included at low dosages (0.15–0.2%) in the diet can be beneficial.^[21] Some studies suggest that chestnut tannins have been shown to have positive effects on silage quality in the round bale silages, in particular reducing NPNs (non protein nitrogen) in the lowest wilting level.^[22] Improved fermentability of soya meal nitrogen in the rumen has also been reported by F. Mathieu and J. P. Jouany (1993).^[23] Studies by S. Gonzalez et al. (2002)^[24] on in vitro ammonia release and dry matter degradation of soybean meal comparing three different types of tannins (quebracho, acacia and chestnut) demonstrated that chestnut tannins are more efficient in protecting soybean meal from in vitro degradation by rumen bacteria.

Condensed tannins inhibit herbivore digestion by binding to consumed plant proteins and making them more difficult for animals to digest, and by interfering with protein absorption and digestive enzymes (for more on that topic, see plant defense against herbivory).
Many tannin-consuming animals secrete a tannin-binding protein (mucin) in their saliva. Tannin-binding capacity of salivary mucin is directly related to its proline content. Advantages in using salivary proline-rich proteins (PRPs) to inactivate tannins are:

PRPs inactivate tannins to a greater extent than do dietary proteins; this results in reduced fecal nitrogen losses
PRPs contain non specific nitrogen and nonessential amino acids; this makes them more convenient for an animal to exploit rather than using up valuable dietary protein

Drinks with tannins

The best-known sources of tannins are tea and wine. See the above articles for more information on the phenolic content of these drinks. Other sources include fruit juices, but not citrus.

It should be noted that, in contrast to previous reports, coffee has not been found to contain tannins. Tannins were not found in any bean sample, and hydrolysable tannins sensu stricto were not detected in pulp. The presence of soluble condensed tannins in Coffea arabica pulp was confirmed at approximately 1%.^[25]

Fruit juices

Although citrus fruits do not themselves contain tannins, orange-colored juices often contain food dyes with tannins. Apple juice, grape juices and berry juices are all high in tannins. Sometimes tannins are even added to juices and ciders to create a more astringent feel to the taste.

Beer

In addition to the alpha acids extracted from hops to provide bitterness in beer, condensed tannins are also present. These originate both from the malt and hops. Especially in Germany, trained brewmasters consider the presence of tannins as a flaw. In some styles, the presence of this astringency is acceptable or even desired, as, for example, in a Flanders red ale.

In lager type beers, the tannins can form a precipitate with specific haze-forming proteins in the beer resulting in turbidity at low temperature. This chill haze can be prevented by removing part of the tannins or part of the haze-forming proteins. Tannins are removed using PVPP, haze-forming proteins by using silica or tannic acid.^[26]

Food items with tannins

Fruits

Pomegranates

Persimmons

Some persimmons are highly astringent and therefore inedible when they are not extremely ripe (to be specific, the Korean, American, and Hachiya or Japanese). This is due to the high level of tannins, and if eaten by humans (and many other animals), the mouth will become completely dry, yet the saliva glands will continue to secrete saliva, which cannot affect the tannin-laced food.^{[clarification needed]}

Berries

Most berries, such as cranberries,^[27] strawberries and blueberries,^[28] contain both hydrolyzable and condensed tannins.

Nuts

Nuts that can be consumed raw such as hazelnuts, walnuts, and pecans contain high amounts of tannins. Almonds feature a lower content. Tannin concentration in the crude extract of these nuts did not directly translate to the same relationships for the condensed fraction.^[29] Acorns contain such high concentrations of tannins that they need to be processed before they can be consumed safely.

The areca nut also contains tannin, which contributes to its antibacterial properties.

Smoked foods

Tannins from the wood of mesquite, cherry, oak, and other woods used in smoking are present on the surface of smoked fish and meat.

Herbs and spices

Cloves, tarragon, cumin, thyme, vanilla, and cinnamon all contain tannins.^[30]

Legumes

Most legumes contain tannins. Red-colored beans contain the most tannins, and white-colored beans have the least. Peanuts without shells have a very low tannin content. Chickpeas (garbanzo beans) have a smaller amount of tannins.^[31]

Chocolate

Chocolate liquor contains about 6% tannins.^[32]

Health effects of tannins

Tannin market

Tannin production began at the beginning of the 19th century with the industrial revolution, to produce tanning material for the need for more leather. Before that time, processes used plant material and were long (up to six months).

There has been a collapse in the vegetable tannin market in the 1950s–1960s, due to the appearance of synthetic tannins, due the scarity of vegetable tannins during World War II. At that time, many small tannin industry sites closed.^[33] Vegetable tannins are estimated to be used for the production of 10–20% of the global leather production.

The cost of the final product depends on the method used to extract the tannins, in particular the use of solvents, alkali and other chemicals used (for instance glycerin). For large quantities, the most cost-effective method is hot water extraction.

Tannic acid is used worldwide as clarifying agent in alcoholic drinks and as aroma ingredient in both alcoholic and soft drinks or juices. Tannins from different botanical origins also find extensive uses in the wine industry.

Uses

Tannins are an important ingredient in the process of tanning leather. Oak bark, mimosa, chestnut and quebracho tree have traditionally been the primary source of tannery tannin, though inorganic tanning agents are also in use today and account for 90% of the world's leather production.^[34]

Tannins produce different colors with ferric chloride (either blue, blue black, or green to greenish-black) according to the type of tannin. Iron gall ink is produced by treating a solution of tannins with iron(II) sulfate.^{[citation needed]}

Tannin is a component in a type of industrial particleboard adhesive developed jointly by the Tanzania Industrial Research and Development Organization and Forintek Labs Canada.^[35] Pinus radiata tannins has been investigated for the production of wood adhesives.^[36]

Condensed tannins, i.e. quebracho tannin, and Hydrolyzable tannins, i.e., chestnut tannin, appear to be able to substitute a high proportion of synthetic phenol in phenol-formaldehyde resins for wood particleboard.

Tannins can be used for production of anti-corrosive primer, sold under brand name-Nox Primer for treatment of rusted steel surfaces prior to painting, rust converter to transform oxidized steel into a smooth sealed surface and rust inhibitor.

The use of resins made of tannins has been investigated to remove mercury and methylmercury from solution.^[37] Immobilized tannins have been tested to recover uranium from seawater.^[38]

Medical uses and potential

Tannins may also be effective in protecting the kidneys. When incubated with red grape juice and red wines with a high content of condensed tannins, the poliovirus, herpes simplex virus, and various enteric viruses are inactivated.^[39]

Tannins have shown potential antiviral,^[40] antibacterial^[41] and antiparasitic effects.^[42]

It is believed that tannins isolated from the stem bark of Myracrodruon urundeuva may have neuroprotective functions capable of reversing 6-hydroxydopamine-induced toxicity. The plant has shown promise as a potential therapeutic agent, which may be beneficial in patients with neurological disease.^[43] Souza et al. discovered that the tannins isolated from the stem bark also have anti-inflammatory and antiulcer activity in rodents, showing a strong antioxidant property with possible therapeutic applications.^[44]

Foods rich in tannins can be used in the treatment of HFE hereditary hemochromatosis, a hereditary disease characterized by excessive absorption of dietary iron, resulting in a pathological increase in total body iron stores.

Producers

There are three main producers of tannins in the world:

Ajinomoto OmniChem NaturalSpecialities, a subsidiary of the Ajinomoto group, is specializing in the tannin production^[45]
Silva Team produces tannins for leather tanning, oenology or other uses^[46]
Unitán, an Argentine company, produces quebracho tannins.

Following companies are not producers but blenders of tannins for specific applications:

AEB group, an Italian company based in Brescia, blends & markets tannins for oenology applications^[47]
Enartis, an Italian company based in San Martino, develops and sells oenological tannins.^[48]

References

Books

Chemie der Gerbstoffe. Maximilian Nierenstein, 1910
Organische Arsenverbindungen und ihre chemotherapeutische Bedeutung. Maximilian Nierenstein, 1913
Incunabula of Tannin Chemistry: A Coll. of Some Early Papers on the Chemistry Chemistry of the Tannins. Maximilian Nierenstein, 1932
The Natural Organic Tannins: History, Chemistry, Distribution. Maximilian Nierenstein and Macgregor Skene, 1934
Chemie der natürlichen Gerbstoffe. Karl Johann Freudenberg, 1920
Tannin, Cellulose, Lignin. Karl Johann Freudenberg, 1933

Notes

^ Katie E. Ferrell; Thorington, Richard W. (2006). Squirrels: the animal answer guide. Baltimore: Johns Hopkins University Press. p. 91. ISBN 0-8018-8402-0.{{cite book}}: CS1 maint: multiple names: authors list (link)
^ McGee, Harold (2004). On food and cooking: the science and lore of the kitchen. New York: Scribner. p. 714. ISBN 0-684-80001-2.
^ Bate-Smith and Swain (1962). "Flavonoid compounds". In Florkin M., Mason H. S (ed.). Comparative biochemistry. Vol. III. New York: Academic Press. pp. 75–809.
^ Simon Mole (1993). "The Systematic Distribution of Tannins in the Leaves of Angiosperms: A Tool for Ecological Studies". Biochemical Systematics and Ecology. 21 (8): 833–846. doi:10.1016/0305-1978(93)90096-A.
^ Kadam, S. S.; Salunkhe, D. K.; Chavan, J. K. (1990). Dietary tannins: consequences and remedies. Boca Raton: CRC Press. p. 177. ISBN 0-8493-6811-1.{{cite book}}: CS1 maint: multiple names: authors list (link)
^ Identification of Molecular Markers Linked to the Trait of Natural Astringency Loss of Japanese Persimmon (Diospyros kaki) Fruit. Shinya Kanzaki, Keizo Yonemori and Akira Sugiura, J. Amer. Soc. Hort. Sci., 2001, 126(1), pages 51–55 (article)
^ "Short-term and long-term effects of tannins on nitrogen mineralisation and litter decomposition in kauri (Agathis australis (D. Don) Lindl.) forests". Eric Verkaik, Anne G. Jongkindet, Frank Berendse, Plant And Soil, 2006, Volume 287, Numbers 1–2, pages 337–345, doi:10.1007/s11104-006-9081-8
^ Tannins, lignins and humic acids in well water on www.gov.ns.ca
^ Preparing Driftwood for Your Freshwater Aquarium
^ Polyflavonoid tannins — a main cause of soft-rot failure in CCA-treated timber
^ Driftwood Do's & Don'ts
^ Tannin and hardwood flooring
^ ^a ^b The Tannin Handbook, Ann E. Hagerman, 1988 (book)
^ "Condensed tannins". Porter L. J., 1989, in Natural Products of Woody Plants I, Rowe J. W. (ed), Springer-Verlag: Berlin, Germany, pages 651–690
^ "Antibacterial activity of leave extracts of Nymphaea lotus (Nymphaeaceae) on Methicillin resistant Staphylococcus aureus (MRSA) and Vancomycin resistant Staphylococcus aureus (VRSA) isolated from clinical samples". Akinjogunla O. J., Yah C. S., Eghafona N. O. and Ogbemudia F. O., Annals of Biological Research, 2010, 1 (2), pages 174–184
^ "Phytochemical Analysis and Antimicrobial Activity Of Scoparia dulcis and Nymphaea lotus". Jonathan Yisa, Australian Journal of Basic and Applied Sciences, 2009, 3(4): pages 3975–3979
^ ^a ^b Notes on Tannins from PharmaXChange.info
^ Tannins, Unknown author
^ Ashutosh Kar (2003). Pharmacognosy And Pharmacobiotechnology. New Age International. pp. 44–. ISBN 978-81-224-1501-8. Retrieved 31 January 2011.
^ Muller-Harvey I., McAllan A. B. (1992). "Tannins: Their biochemistry and nutritional properties". Adv. Plant Cell Biochem. And Biotechnol. 1: 151–217.
^ Schiavone A., Guo K., Tassone S.; et al. (2008). "Effects of a natural extract of chestnut wood on digestibility, performance traits, and nitrogen balance of broiler chicks". Poult. Sci. 87 (3): 521–7. doi:10.3382/ps.2007-00113. PMID 18281579. {{cite journal}}: Explicit use of et al. in: |author= (help); Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
^ Tabacco E., Borreani G., Crovetto G. M., Galassi G., Colombo D., Cavallarin L. (1 December 2006). "Effect of chestnut tannin on fermentation quality, proteolysis, and protein rumen degradability of alfalfa silage". J. Dairy Sci. 89 (12): 4736–46. doi:10.3168/jds.S0022-0302(06)72523-1. PMID 17106105.{{cite journal}}: CS1 maint: multiple names: authors list (link)
^ Mathieu F., Jouany J. P. (1993). "Effect of chestnut tannin on the fermentability of soyabean meal nitrogen in the rumen". Ann Zootech. 42 (2): 127. doi:10.1051/animres:19930210.
^ González S., Pabón M. L., Carulla J. (2002). "Effects of tannins on in vitro ammonia release and dry matter degradation of soybean meal". Arch. Latinoam. Prod. Anim. 10 (2): 97–101.{{cite journal}}: CS1 maint: multiple names: authors list (link)
^ Clifford M. N., Ramirez-Martinez J. R. (1991). "Tannins in wet-processed coffee beans and coffee pulp". Food Chemistry. 40 (2): 191–200. doi:10.1016/0308-8146(91)90102-T.
^ http://www.natural-specialities.com/natural-specialities/PDF/Applications/BR02%20overview%20fact%20sheet%20version%202.1.pdf
^ Vattem D. A., Ghaedian R., Shetty K. (2005). "Enhancing health benefits of berries through phenolic antioxidant enrichment: focus on cranberry" (PDF). Asia Pac J Clin Nutr. 14 (2): 120–30. PMID 15927928.{{cite journal}}: CS1 maint: multiple names: authors list (link)
^ Puupponen-Pimiä R., Nohynek L., Meier C.; et al. (2001). "Antimicrobial properties of phenolic compounds from berries". J. Appl. Microbiol. 90 (4): 494–507. doi:10.1046/j.1365-2672.2001.01271.x. PMID 11309059. {{cite journal}}: Explicit use of et al. in: |author= (help); Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
^ http://google.com/search?q=cache:K-qF4vdf8a8J:www.icomst.helsinki.fi/icomst2008/Paper%2520CD/General%2520speakers%2Bposters-3p%2520papers/Session2/2B/2B.3.Amarowicz.pdf+tannin+%22nuts%22&hl=en&ct=clnk&cd=10&gl=us ^{[dead link]}
^ Navia, Jeanette. "Could Tannins Explain Classic Migraine Triggers?" 1988
^ Reed J. D. (1 May 1995). "Nutritional toxicology of tannins and related polyphenols in forage legumes". J. Anim. Sci. 73 (5): 1516–28. PMID 7665384.
^ Robert L. Wolke; Marlene Parrish (29 March 2005). What Einstein told his cook 2: the sequel: further adventures in kitchen science. W. W. Norton & Company. p. 433. ISBN 978-0-393-05869-7.
^ "The Status of Mangrove Ecosystems: Trends in the Utilisation and Management of Mangrove Resources". D. Macintosh and S. Zisman
^ Marion Kite; Roy Thomson (2006). Conservation of leather and related materials. Butterworth-Heinemann. p. 23. ISBN 978-0-7506-4881-3.
^ Bisanda E. T. N., Ogola W. O., Tesha J. V. (August 2003). "Characterisation of tannin resin blends for particle board applications". Cement and Concrete Composites. 25 (6): 593–8. doi:10.1016/S0958-9465(02)00072-0.{{cite journal}}: CS1 maint: multiple names: authors list (link)
^ Li, Jingge; Maplesden, Frances (1998). "Commercial production of tannins from radiata pine bark for wood adhesives" (PDF). IPENZ Transactions. 25 (1/EMCh).{{cite journal}}: CS1 maint: multiple names: authors list (link)
^ Torres J., Olivares S., De La Rosa D., Lima L., Martínez F., Munita C. S., Favaro D. I. T. (1999). "Removal of mercury(II) and methylmercury from solution by tannin adsorbents". Journal of Radioanalytical and Nuclear Chemistry. 240 (1): 361–5. doi:10.1007/BF02349180.{{cite journal}}: CS1 maint: multiple names: authors list (link)
^ Takashi Sakaguchia, Akira Nakajimaa (June 1987). "Recovery of Uranium from Seawater by Immobilized Tannin". Separation Science and Technology. 22 (6): 1609–23. doi:10.1080/01496398708058421.
^ Bajaj, Y. P. S. (1988). Medicinal and aromatic plants. Biotechnology in agriculture and forestry. Vol. 24. Berlin: Springer-Verlag. ISBN 0-387-56008-4.
^ Lü L., Liu S. W., Jiang S. B., Wu S. G. (2004). "Tannin inhibits HIV-1 entry by targeting gp41". Acta Pharmacol. Sin. 25 (2): 213–8. PMID 14769212. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
^ Akiyama H., Fujii K., Yamasaki O., Oono T., Iwatsuki K. (2001). "Antibacterial action of several tannins against Staphylococcus aureus". J. Antimicrob. Chemother. 48 (4): 487–91. doi:10.1093/jac/48.4.487. PMID 11581226. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
^ Kolodziej H., Kiderlen A. F. (2005). "Antileishmanial activity and immune modulatory effects of tannins and related compounds on Leishmania parasitised RAW 264.7 cells". Phytochemistry. 66 (17): 2056–71. doi:10.1016/j.phytochem.2005.01.011. PMID 16153409. {{cite journal}}: Unknown parameter |month= ignored (help)
^ Nobre-Junior, Helio V.; et al. (2007). "Neuroprotective Actions of Tannins from Myracrodruon urundeuva on 6-Hydroxydopamine-Induced Neuronal Cell Death". Journal of Herbs, Spices & Medicinal Plants. 13 (2). Haworth Press. Retrieved 8 November 2007. {{cite journal}}: Cite has empty unknown parameter: |coauthors= (help); Explicit use of et al. in: |first= (help)
^ Souza, S. M. C.; Aquino, L. C.; Milach Jr, A. C.; Bandeira, M. A.; Nobre, M. E.; Viana, G. S.; et al. (2006). "Antiinflammatory and antiulcer properties of tannins from Myracrodruon urundeuva Allemão (Anacardiaceae) in Rodents". Phytotherapy Research. 21 (3). John Wiley & Sons: 220–225. doi:10.1002/ptr.2011. PMID 17154231. {{cite journal}}: Cite has empty unknown parameter: |coauthors= (help); Explicit use of et al. in: |first= (help)
^ www.natural-specialities.com
^ Products on www.silvateam.com
^ Oenological tannins on www.aeb-group.com
^ Tannins on www.enartis.com

Calvi L., Mwalongo G. C. J., Mwingira B. A., Riedl B., Shields J. A. (1995). "Characterization of Wattle-Tannin-Based Adhesives for Tanzania". Holzforchung. 49 (2).{{cite journal}}: CS1 maint: multiple names: authors list (link)

External links

Tannins: fascinating but sometimes dangerous molecules
Template:PDFlink
Haslam, Edwin (1989). Plant polyphenols: vegetable tannins revisited. CUP Archive. ISBN 978-0-521-32189-1.

[1] Katie E. Ferrell; Thorington, Richard W. (2006). Squirrels: the animal answer guide. Baltimore: Johns Hopkins University Press. p. 91. ISBN 0-8018-8402-0.{{cite book}}: CS1 maint: multiple names: authors list (link)

[2] McGee, Harold (2004). On food and cooking: the science and lore of the kitchen. New York: Scribner. p. 714. ISBN 0-684-80001-2.

[Bate-Smith-3] Bate-Smith and Swain (1962). "Flavonoid compounds". In Florkin M., Mason H. S (ed.). Comparative biochemistry. Vol. III. New York: Academic Press. pp. 75–809.

[4] Simon Mole (1993). "The Systematic Distribution of Tannins in the Leaves of Angiosperms: A Tool for Ecological Studies". Biochemical Systematics and Ecology. 21 (8): 833–846. doi:10.1016/0305-1978(93)90096-A.

[5] Kadam, S. S.; Salunkhe, D. K.; Chavan, J. K. (1990). Dietary tannins: consequences and remedies. Boca Raton: CRC Press. p. 177. ISBN 0-8493-6811-1.{{cite book}}: CS1 maint: multiple names: authors list (link)

[6] Identification of Molecular Markers Linked to the Trait of Natural Astringency Loss of Japanese Persimmon (Diospyros kaki) Fruit. Shinya Kanzaki, Keizo Yonemori and Akira Sugiura, J. Amer. Soc. Hort. Sci., 2001, 126(1), pages 51–55 (article)

[7] "Short-term and long-term effects of tannins on nitrogen mineralisation and litter decomposition in kauri (Agathis australis (D. Don) Lindl.) forests". Eric Verkaik, Anne G. Jongkindet, Frank Berendse, Plant And Soil, 2006, Volume 287, Numbers 1–2, pages 337–345, doi:10.1007/s11104-006-9081-8

[8] Tannins, lignins and humic acids in well water on www.gov.ns.ca

[9] Preparing Driftwood for Your Freshwater Aquarium

[10] Polyflavonoid tannins — a main cause of soft-rot failure in CCA-treated timber

[11] Driftwood Do's & Don'ts

[12] Tannin and hardwood flooring

[Hagerman1988-13] The Tannin Handbook, Ann E. Hagerman, 1988 (book)

[14] "Condensed tannins". Porter L. J., 1989, in Natural Products of Woody Plants I, Rowe J. W. (ed), Springer-Verlag: Berlin, Germany, pages 651–690

[15] "Antibacterial activity of leave extracts of Nymphaea lotus (Nymphaeaceae) on Methicillin resistant Staphylococcus aureus (MRSA) and Vancomycin resistant Staphylococcus aureus (VRSA) isolated from clinical samples". Akinjogunla O. J., Yah C. S., Eghafona N. O. and Ogbemudia F. O., Annals of Biological Research, 2010, 1 (2), pages 174–184

[16] "Phytochemical Analysis and Antimicrobial Activity Of Scoparia dulcis and Nymphaea lotus". Jonathan Yisa, Australian Journal of Basic and Applied Sciences, 2009, 3(4): pages 3975–3979

[ref_1-17] Notes on Tannins from PharmaXChange.info

[18] Tannins, Unknown author

[19] Ashutosh Kar (2003). Pharmacognosy And Pharmacobiotechnology. New Age International. pp. 44–. ISBN 978-81-224-1501-8. Retrieved 31 January 2011.

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[21] Schiavone A., Guo K., Tassone S.; et al. (2008). "Effects of a natural extract of chestnut wood on digestibility, performance traits, and nitrogen balance of broiler chicks". Poult. Sci. 87 (3): 521–7. doi:10.3382/ps.2007-00113. PMID 18281579. {{cite journal}}: Explicit use of et al. in: |author= (help); Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)

[22] Tabacco E., Borreani G., Crovetto G. M., Galassi G., Colombo D., Cavallarin L. (1 December 2006). "Effect of chestnut tannin on fermentation quality, proteolysis, and protein rumen degradability of alfalfa silage". J. Dairy Sci. 89 (12): 4736–46. doi:10.3168/jds.S0022-0302(06)72523-1. PMID 17106105.{{cite journal}}: CS1 maint: multiple names: authors list (link)

[23] Mathieu F., Jouany J. P. (1993). "Effect of chestnut tannin on the fermentability of soyabean meal nitrogen in the rumen". Ann Zootech. 42 (2): 127. doi:10.1051/animres:19930210.

[24] González S., Pabón M. L., Carulla J. (2002). "Effects of tannins on in vitro ammonia release and dry matter degradation of soybean meal". Arch. Latinoam. Prod. Anim. 10 (2): 97–101.{{cite journal}}: CS1 maint: multiple names: authors list (link)

[25] Clifford M. N., Ramirez-Martinez J. R. (1991). "Tannins in wet-processed coffee beans and coffee pulp". Food Chemistry. 40 (2): 191–200. doi:10.1016/0308-8146(91)90102-T.

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[27] Vattem D. A., Ghaedian R., Shetty K. (2005). "Enhancing health benefits of berries through phenolic antioxidant enrichment: focus on cranberry" (PDF). Asia Pac J Clin Nutr. 14 (2): 120–30. PMID 15927928.{{cite journal}}: CS1 maint: multiple names: authors list (link)

[28] Puupponen-Pimiä R., Nohynek L., Meier C.; et al. (2001). "Antimicrobial properties of phenolic compounds from berries". J. Appl. Microbiol. 90 (4): 494–507. doi:10.1046/j.1365-2672.2001.01271.x. PMID 11309059. {{cite journal}}: Explicit use of et al. in: |author= (help); Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)

[29] ttp://google.com/search?q=cache:K-qF4vdf8a8J:www.icomst.helsinki.fi/icomst2008/Paper%2520CD/General%2520speakers%2Bposters-3p%2520papers/Session2/2B/2B.3.Amarowicz.pdf+tannin+%22nuts%22&hl=en&ct=clnk&cd=10&gl=us ^{[dead link]}

[30] Navia, Jeanette. "Could Tannins Explain Classic Migraine Triggers?" 1988

[31] Reed J. D. (1 May 1995). "Nutritional toxicology of tannins and related polyphenols in forage legumes". J. Anim. Sci. 73 (5): 1516–28. PMID 7665384.

[32] Robert L. Wolke; Marlene Parrish (29 March 2005). What Einstein told his cook 2: the sequel: further adventures in kitchen science. W. W. Norton & Company. p. 433. ISBN 978-0-393-05869-7.

[33] "The Status of Mangrove Ecosystems: Trends in the Utilisation and Management of Mangrove Resources". D. Macintosh and S. Zisman

[34] Marion Kite; Roy Thomson (2006). Conservation of leather and related materials. Butterworth-Heinemann. p. 23. ISBN 978-0-7506-4881-3.

[35] Bisanda E. T. N., Ogola W. O., Tesha J. V. (August 2003). "Characterisation of tannin resin blends for particle board applications". Cement and Concrete Composites. 25 (6): 593–8. doi:10.1016/S0958-9465(02)00072-0.{{cite journal}}: CS1 maint: multiple names: authors list (link)

[36] Li, Jingge; Maplesden, Frances (1998). "Commercial production of tannins from radiata pine bark for wood adhesives" (PDF). IPENZ Transactions. 25 (1/EMCh).{{cite journal}}: CS1 maint: multiple names: authors list (link)

[37] Torres J., Olivares S., De La Rosa D., Lima L., Martínez F., Munita C. S., Favaro D. I. T. (1999). "Removal of mercury(II) and methylmercury from solution by tannin adsorbents". Journal of Radioanalytical and Nuclear Chemistry. 240 (1): 361–5. doi:10.1007/BF02349180.{{cite journal}}: CS1 maint: multiple names: authors list (link)

[38] Takashi Sakaguchia, Akira Nakajimaa (June 1987). "Recovery of Uranium from Seawater by Immobilized Tannin". Separation Science and Technology. 22 (6): 1609–23. doi:10.1080/01496398708058421.

[39] Bajaj, Y. P. S. (1988). Medicinal and aromatic plants. Biotechnology in agriculture and forestry. Vol. 24. Berlin: Springer-Verlag. ISBN 0-387-56008-4.

[40] Lü L., Liu S. W., Jiang S. B., Wu S. G. (2004). "Tannin inhibits HIV-1 entry by targeting gp41". Acta Pharmacol. Sin. 25 (2): 213–8. PMID 14769212. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)

[41] Akiyama H., Fujii K., Yamasaki O., Oono T., Iwatsuki K. (2001). "Antibacterial action of several tannins against Staphylococcus aureus". J. Antimicrob. Chemother. 48 (4): 487–91. doi:10.1093/jac/48.4.487. PMID 11581226. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)

[42] Kolodziej H., Kiderlen A. F. (2005). "Antileishmanial activity and immune modulatory effects of tannins and related compounds on Leishmania parasitised RAW 264.7 cells". Phytochemistry. 66 (17): 2056–71. doi:10.1016/j.phytochem.2005.01.011. PMID 16153409. {{cite journal}}: Unknown parameter |month= ignored (help)

[ahpg-43] Nobre-Junior, Helio V.; et al. (2007). "Neuroprotective Actions of Tannins from Myracrodruon urundeuva on 6-Hydroxydopamine-Induced Neuronal Cell Death". Journal of Herbs, Spices & Medicinal Plants. 13 (2). Haworth Press. Retrieved 8 November 2007. {{cite journal}}: Cite has empty unknown parameter: |coauthors= (help); Explicit use of et al. in: |first= (help)

[aapt-44] Souza, S. M. C.; Aquino, L. C.; Milach Jr, A. C.; Bandeira, M. A.; Nobre, M. E.; Viana, G. S.; et al. (2006). "Antiinflammatory and antiulcer properties of tannins from Myracrodruon urundeuva Allemão (Anacardiaceae) in Rodents". Phytotherapy Research. 21 (3). John Wiley & Sons: 220–225. doi:10.1002/ptr.2011. PMID 17154231. {{cite journal}}: Cite has empty unknown parameter: |coauthors= (help); Explicit use of et al. in: |first= (help)

[45] www.natural-specialities.com

[46] Products on www.silvateam.com

[47] Oenological tannins on www.aeb-group.com

[48] Tannins on www.enartis.com

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@@ Line 9: / Line 9: @@
 The tannin compounds are widely distributed in many species of plants, where they play a role in protection from predation, and perhaps also as pesticides, and in plant growth regulation.<ref>{{cite book |author=Katie E. Ferrell; Thorington, Richard W. |title=Squirrels: the animal answer guide |publisher=Johns Hopkins University Press |location=Baltimore |year=2006 |page=91 |isbn=0-8018-8402-0 }}</ref> The [[astringency]] from the tannins is what causes the dry and puckery feeling in the mouth following the consumption of unripened fruit or red wine.<ref>{{cite book |author=McGee, Harold |title=On food and cooking: the science and lore of the kitchen |publisher=Scribner |location=New York |year=2004 |page=714 |isbn=0-684-80001-2 }}</ref> Likewise, the destruction or modification of tannins with time plays an important role in the [[ripening of fruit (wine)|ripening of fruit]] and the [[aging of wine]].
-Tannins have [[molecular weight]]s ranging from 500 to over 3,000<ref name="Bate-Smith">{{cite book |author=Bate-Smith and Swain |chapter=Flavonoid compounds |editor=Florkin M., Mason H.S. |title=Comparative biochemistry |publisher=Academic Press |location=New York |year=1962 |pages=75–809 |volume=III }}</ref> ([[gallic acid]] [[ester]]s) and up to 20,000 (proanthocyanidins). Tannins are incompatible with [[alkali]]s, [[gelatin]], heavy metals, [[iron]], [[limewater]], metallic salts, strong oxidizing agents and [[zinc sulfate]], since they form [[Coordination complex|complex]]es and precipitate in aqueous solution.
+Tannins have [[molecular weight]]s ranging from 500 to over 3,000<ref name="Bate-Smith">{{cite book |author=Bate-Smith and Swain |chapter=Flavonoid compounds |editor=Florkin M., Mason H. S |title=Comparative biochemistry |publisher=Academic Press |location=New York |year=1962 |pages=75–809 |volume=III }}</ref> ([[gallic acid]] [[ester]]s) and up to 20,000 (proanthocyanidins). Tannins are incompatible with [[alkali]]s, [[gelatin]], heavy metals, [[iron]], [[limewater]], metallic salts, strong oxidizing agents and [[zinc sulfate]], since they form [[Coordination complex|complex]]es and precipitate in aqueous solution.
 == History ==
-Austrian chemist [[Heinrich Hlasiwetz]] (1825-1875) worked on tannins. The biochemist [[Maximilian Nierenstein]] studied the natural tannins in 1934. The chemist [[Karl Johann Freudenberg]] studied them in the 1920s.
+Austrian chemist [[Heinrich Hlasiwetz]] (1825–1875) worked on tannins. The biochemist [[Maximilian Nierenstein]] studied the natural tannins in 1934. The chemist [[Karl Johann Freudenberg]] studied them in the 1920s.
 == Occurrence ==
-Tannins are distributed in species throughout the [[plant kingdom]]. They are commonly found in both [[gymnosperm]]s as well as [[angiosperm]]s. Mole<ref>{{cite journal |author=Simon Mole |title=The Systematic Distribution of Tannins in the  Leaves of Angiosperms:  A Tool for  Ecological Studies &#124; périodique =  |journal=Biochemical Systematics and Ecology |volume=21 |issue=8 |pages=833–846 |year=1993|doi=10.1016/0305-1978(93)90096-A}}</ref> (1993) studied the distribution of tannin in 180 families of [[dicotyledon]]s and 44 families of [[monocotyledon]]s (Cronquist). Most families of dicot contain tannin-free species (tested by their ability to precipitate proteins).
+Tannins are distributed in species throughout the [[plant kingdom]]. They are commonly found in both [[gymnosperm]]s as well as [[angiosperm]]s. Mole<ref>{{cite journal |author=Simon Mole |title=The Systematic Distribution of Tannins in the Leaves of Angiosperms: A Tool for Ecological Studies |journal=Biochemical Systematics and Ecology |volume=21 |issue=8 |pages=833–846 |year=1993|doi=10.1016/0305-1978(93)90096-A}}</ref> (1993) studied the distribution of tannin in 180 families of [[dicotyledon]]s and 44 families of [[monocotyledon]]s (Cronquist). Most families of dicot contain tannin-free species (tested by their ability to precipitate proteins).
 The best known families of which all species tested contain tannin are: [[Aceraceae]], [[Actinidiaceae]], [[Anacardiaceae]], [[Bixaceae]], [[Burseraceae]], [[Combretaceae]], [[Dipterocarpaceae]], [[Ericaceae]], [[Grossulariaceae]], [[Myricaceae]] for dicot and [[Najadaceae]] and [[Typhaceae]] in Monocot. To the family of the oak, [[Fagaceae]], 73% of the species tested (N = 22) contain tannin. For those of acacias, [[Mimosaceae]], only 39% of the species tested (N = 28) contain tannin, among [[Solanaceae]] rate drops to 6% and 4% for the [[Asteraceae]]. Some families like the [[Boraginaceae]], [[Cucurbitaceae]], [[Papaveraceae]] contain no tannin-rich species.
@@ Line 28: / Line 28: @@
 === Cellular localization ===
-Tannins, by definition, precipitate proteins. In this condition, they must be stored in organelles able to withstand the protein precipitation process. [[Idioblast]]s are isolated plant cells which differ from neighboring tissues and contain non-living substances. They have various functions such as storage of reserves, excretory materials, pigments, and minerals. They could contain oil, latex, gum, resin or pigments etc. They also can contain tannins. In Japanese persimmon (''[[Diospyros kaki]]'') fruits, tannin is accumulated in the vacuole of tannin cells, which are idioblasts of parenchyma cells in the flesh.<ref>Identification of Molecular Markers Linked to the Trait of Natural Astringency Loss of Japanese Persimmon (Diospyros kaki) Fruit. Shinya Kanzaki, Keizo Yonemori and Akira Sugiura, J. AMER. SOC. HORT. SCI., 2001, 126(1), pages 51–55 ([http://journal.ashspublications.org/content/126/1/51.full.pdf+html article])</ref>
+Tannins, by definition, precipitate proteins. In this condition, they must be stored in organelles able to withstand the protein precipitation process. [[Idioblast]]s are isolated plant cells which differ from neighboring tissues and contain non-living substances. They have various functions such as storage of reserves, excretory materials, pigments, and minerals. They could contain oil, latex, gum, resin or pigments etc. They also can contain tannins. In Japanese persimmon (''[[Diospyros kaki]]'') fruits, tannin is accumulated in the vacuole of tannin cells, which are idioblasts of parenchyma cells in the flesh.<ref>Identification of Molecular Markers Linked to the Trait of Natural Astringency Loss of Japanese Persimmon (''Diospyros kaki'') Fruit. Shinya Kanzaki, Keizo Yonemori and Akira Sugiura, ''J. Amer. Soc. Hort. Sci.'', 2001, 126(1), pages 51–55 ([http://journal.ashspublications.org/content/126/1/51.full.pdf+html article])</ref>
 === Presence in soils ===
 The [[convergent evolution]] of tannin-rich plant communities has occurred on nutrient-poor acidic soils throughout the world. Tannins were once believed to function as anti-herbivore defenses, but more and more ecologists now recognize them as important controllers of decomposition and nitrogen cycling processes. As concern grows about global warming, there is great interest to better understand the role of polyphenols as regulators of carbon cycling, in particular in northern boreal forests.
-Leaf litter and other decaying parts of a kauri (''[[Agathis australis]]''), a tree species found in New Zealand, decompose much more slowly than those of most other species. Besides its acidity, the plant also bears substances such as waxes and phenols, most notably tannins,<ref>Short-term and long-term effects of tannins on nitrogen mineralisation and litter decomposition in kauri (Agathis australis (D. Don) Lindl.) forests. Eric Verkaik, Anne G. JongkindetFrank Berendse, Plant And Soil, 2006, Volume 287, Numbers 1-2, pages 337-345, {{doi|10.1007/s11104-006-9081-8}}</ref> that are harmful to [[microorganism]]s.
+Leaf litter and other decaying parts of a kauri (''[[Agathis australis]]''), a tree species found in New Zealand, decompose much more slowly than those of most other species. Besides its acidity, the plant also bears substances such as waxes and phenols, most notably tannins,<ref>"Short-term and long-term effects of tannins on nitrogen mineralisation and litter decomposition in kauri (''Agathis australis'' (D. Don) Lindl.) forests". Eric Verkaik, Anne G. Jongkindet, Frank Berendse, ''Plant And Soil'', 2006, Volume 287, Numbers 1–2, pages 337–345, {{doi|10.1007/s11104-006-9081-8}}</ref> that are harmful to [[microorganism]]s.
 === Presence in water and wood ===
 [[File:Tannin rich fresh water draining into Cox Bight from Freney Lagoon.jpg|thumb|Tannin rich fresh water draining into Cox Bight from Freney Lagoon, Southwest Conservation Area, Tasmania, Australia]]
-The [[Leaching (chemistry)|leaching]] of highly [[water]] [[Solubility|soluble]]<ref>[http://webcache.googleusercontent.com/search?q=cache:uzG3Ckud3BIJ:en.wikipedia.org/wiki/Tannic_acid+highly+water+soluable+tannin&cd=2&hl=en&ct=clnk&gl=us&source=www.google.com Tannic acid (Wikipedia)]</ref> tannins from decaying vegetation and leaves along a stream may produce what is known as a [[blackwater river]]. Water flowing out of [[bog]]s has a characteristic brown color from dissolved [[peat]] tannins. The presence of tannins (or [[humic acid]]) in [[Water well|well water]] can make it smell bad or taste bitter, but not be unsafe to drink.<ref>[http://www.gov.ns.ca/nse/water/docs/droponwaterFAQ_HumicSubstances.pdf Tannins, lignins and humic acids in well water on www.gov.ns.ca]</ref>
+The [[Leaching (chemistry)|leaching]] of highly [[water]] [[Solubility|soluble]] tannins from decaying vegetation and leaves along a stream may produce what is known as a [[blackwater river]]. Water flowing out of [[bog]]s has a characteristic brown color from dissolved [[peat]] tannins. The presence of tannins (or [[humic acid]]) in [[Water well|well water]] can make it smell bad or taste bitter, but not be unsafe to drink.<ref>[http://www.gov.ns.ca/nse/water/docs/droponwaterFAQ_HumicSubstances.pdf Tannins, lignins and humic acids in well water on www.gov.ns.ca]</ref>
 [[File:Bogwood Betta.jpg|thumb|left|[[Bog-wood]] (similar to, but not, [[driftwood]]) in an [[aquarium]], turning the [[water]] a tea-like brown]]
@@ Line 47: / Line 47: @@
 == Extraction ==
-There is no single protocol for [[Extraction (chemistry)|extracting]] tannins from all plant material. The procedures used for tannins are widely variable.<ref name=Hagerman1988>The Tannin Handbook, Ann E. Hagerman, 1988 ([http://www.users.muohio.edu/hagermae/ book])</ref> It may be that [[acetone]] in the extraction solvent increases the total yield by inhibiting interactions between tannins and [[protein]]s during extraction<ref name=Hagerman1988/> or even by breaking hydrogen bonds between tannin-protein complexes.<ref>Condensed tannins. Porter LJ, 1989, in Natural Products of Woody Plants I, Rowe JW (ed), Springer-Verlag: Berlin, Germany, pages 651-690</ref>
+There is no single protocol for [[Extraction (chemistry)|extracting]] tannins from all plant material. The procedures used for tannins are widely variable.<ref name=Hagerman1988>''The Tannin Handbook'', Ann E. Hagerman, 1988 ([http://www.users.muohio.edu/hagermae/ book])</ref> It may be that [[acetone]] in the extraction solvent increases the total yield by inhibiting interactions between tannins and [[protein]]s during extraction<ref name=Hagerman1988/> or even by breaking hydrogen bonds between tannin-protein complexes.<ref>"Condensed tannins". Porter L. J., 1989, in ''Natural Products of Woody Plants I'', Rowe J. W. (ed), Springer-Verlag: Berlin, Germany, pages 651–690</ref>
 == Tests for tannins ==
-; gold beater skin test :
+; gold beater skin test:
 When [[Goldbeater's skin|gold beater skin]] or ox skin is dipped in [[Hydrochloric acid|HCl]] and treated with 1% [[Iron(II) sulfate|FeSO<sub>4</sub>]] solution. After washing with water, it gives a blue black colour.
 ;KOH test:
-cm3 of freshly prepared 10% KOH is added to 1&nbsp;cm<sup>3</sup> of the extract. A dirty white precipitate indicates the presence of tannins.
+&nbsp;cm<sup>3</sup> of freshly prepared 10% KOH is added to 1&nbsp;cm<sup>3</sup> of the extract. A dirty white precipitate indicates the presence of tannins.
-; [[Ferric chloride test|Ferric chloride (FeCl3) test]]:
+; [[Ferric chloride test|Ferric chloride (FeCl<sub>3</sub>) test]]:
-It is rather a test for [[natural phenol|phenolics]] in general. Powdered plant leaves of the test plant (1.0 g) are weighed into a beaker and 10 ml of distilled water are added. The mixture is boiled for five minutes. Two drops of 5% FeCl3 are then added. Production of a greenish precipitate was an indication of the presence of tannins.<ref>Antibacterial activity of leave extracts of Nymphaea lotus (Nymphaeaceae) on Methicillin resistant Staphylococcus aureus (MRSA) and Vancomycin resistant
+It is rather a test for [[natural phenol|phenolics]] in general. Powdered plant leaves of the test plant (1.0 g) are weighed into a beaker and 10 ml of distilled water are added. The mixture is boiled for five minutes. Two drops of 5% FeCl<sub>3</sub> are then added. Production of a greenish precipitate was an indication of the presence of tannins.<ref>"Antibacterial activity of leave extracts of ''Nymphaea lotus'' (Nymphaeaceae) on Methicillin resistant ''Staphylococcus aureus'' (MRSA) and Vancomycin resistant ''Staphylococcus aureus'' (VRSA) isolated from clinical samples". Akinjogunla O. J., Yah C. S., Eghafona N. O. and Ogbemudia F. O., ''Annals of Biological Research'', 2010, 1 (2), pages 174–184</ref> Alternatively, a portion of the water extract is diluted with distilled water in a ratio of 1:4 and few drops of 10% ferric chloride solution is added. A blue or green colour indicates the presence of tannins (Evans, 1989).<ref>"Phytochemical Analysis and Antimicrobial Activity Of ''Scoparia dulcis'' and ''Nymphaea lotus''". Jonathan Yisa, ''Australian Journal of Basic and Applied Sciences'', 2009, 3(4): pages 3975–3979</ref>
-Staphylococcus aureus (VRSA) isolated from clinical samples. Akinjogunla OJ, Yah CS, Eghafona NO and Ogbemudia FO, Annals of Biological Research, 2010, 1 (2), pages 174-184</ref> Alternatively, a portion of the water extract is diluted with distilled water in a ratio of 1:4 and few drops of 10% ferric chloride solution is added. A blue or green colour indicates the presence of tannins (Evans,1989).<ref>Phytochemical Analysis and Antimicrobial Activity Of Scoparia Dulcis and Nymphaea Lotus. Jonathan Yisa, Australian Journal of Basic and Applied Sciences, 2009, 3(4): pages 3975-3979</ref>
 == Classes of tannins ==
@@ Line 86: / Line 85: @@
 * [[flavan-3-ol]]s (''Catechins''): [[Acacia]], [[catechu]], [[Theobroma cacao|cocoa]], [[guarana]]
 * [[Chlorogenic acid]]: [[Nux vomica (herbalism)|Nux-vomica]], [[coffee]], [[Mate (beverage)|mate]]
-* [[Ipecacuanhic acid]]: [[Carapichea ipecacuanha]]
+* [[Ipecacuanhic acid]]: ''[[Carapichea ipecacuanha]]''
 == Nutrition ==
-Tannins have traditionally been considered [[Antinutrient|antinutritional]] but it is now known that their beneficial or antinutritional properties depend upon their chemical structure and dosage. The new technologies used to analyze molecular and chemical structures have shown that a division into condensed and hydrolyzable tannins is far too simplistic.<ref>{{cite journal |author=Muller-Harvey I, McAllan AB |title=Tannins: Their biochemistry and nutritional properties |journal=Adv. Plant Cell Biochem. And Biotechnol. |volume=1 |pages=151–217 |year=1992}}</ref> Recent studies have demonstrated that products containing [[chestnut]] tannins included at low dosages (0.15–0.2 %) in the diet can be beneficial.<ref>{{cite journal |author=Schiavone A, Guo K, Tassone S, ''et al.'' |title=Effects of a natural extract of chestnut wood on digestibility, performance traits, and nitrogen balance of broiler chicks |journal=Poult. Sci. |volume=87 |issue=3 |pages=521–7 |year=2008 |month=March |pmid=18281579 |doi=10.3382/ps.2007-00113 |url=http://ps.fass.org/cgi/pmidlookup?view=long&pmid=18281579}}</ref> Some studies suggest that chestnut tannins have been shown to have positive effects on [[silage]] quality  in the [[Baler#Silage or haylage bales|round bale silages]], in particular reducing [[Non-protein nitrogen|NPN]]s (non protein nitrogen) in the lowest wilting level.<ref>{{cite journal |author=Tabacco E, Borreani G, Crovetto GM, Galassi G, Colombo D, Cavallarin L |title=Effect of chestnut tannin on fermentation quality, proteolysis, and protein rumen degradability of alfalfa silage |journal=J. Dairy Sci. |volume=89 |issue=12 |pages=4736–46 |date=1 December 2006|pmid=17106105 |url=http://jds.fass.org/cgi/pmidlookup?view=long&pmid=17106105 |doi=10.3168/jds.S0022-0302(06)72523-1 }}</ref> Improved fermentability of [[Soybean|soya meal]] nitrogen in the [[rumen]] has also been reported by F. Mathieu and J.P. Jouany (1993).<ref>{{cite journal |doi=10.1051/animres:19930210 |author=Mathieu F, Jouany JP |title=Effect of chestnut tannin on the fermentability of soyabean meal nitrogen in the rumen |journal=Ann Zootech |volume=42 |page=127 |year=1993 |issue=2 }}</ref> Studies by S. Gonzalez et al. (2002)<ref>{{cite journal |author=González S, Pabón ML, Carulla J |title=Effects of tannins on in vitro ammonia release and dry matter degradation of soybean meal |journal=Arch. Latinoam. Prod. Anim. |volume=10 |issue=2 |pages=97–101 |year=2002}}</ref> on ''in vitro'' ammonia release and dry matter degradation of soybean meal comparing three different types of tannins ([[quebracho tannin|quebracho]], [[acacia]] and chestnut) demonstrated that chestnut tannins are more efficient in protecting soybean meal from ''in vitro'' degradation by rumen bacteria.
+Tannins have traditionally been considered [[Antinutrient|antinutritional]] but it is now known that their beneficial or antinutritional properties depend upon their chemical structure and dosage. The new technologies used to analyze molecular and chemical structures have shown that a division into condensed and hydrolyzable tannins is far too simplistic.<ref>{{cite journal |author=Muller-Harvey I., McAllan A. B. |title=Tannins: Their biochemistry and nutritional properties |journal=Adv. Plant Cell Biochem. And Biotechnol. |volume=1 |pages=151–217 |year=1992}}</ref> Recent studies have demonstrated that products containing [[chestnut]] tannins included at low dosages (0.15–0.2%) in the diet can be beneficial.<ref>{{cite journal |author=Schiavone A., Guo K., Tassone S., ''et al.'' |title=Effects of a natural extract of chestnut wood on digestibility, performance traits, and nitrogen balance of broiler chicks |journal=Poult. Sci. |volume=87 |issue=3 |pages=521–7 |year=2008 |month=March |pmid=18281579 |doi=10.3382/ps.2007-00113 |url=http://ps.fass.org/cgi/pmidlookup?view=long&pmid=18281579}}</ref> Some studies suggest that chestnut tannins have been shown to have positive effects on [[silage]] quality in the [[Baler#Silage or haylage bales|round bale silages]], in particular reducing [[Non-protein nitrogen|NPN]]s (non protein nitrogen) in the lowest wilting level.<ref>{{cite journal |author=Tabacco E., Borreani G., Crovetto G. M., Galassi G., Colombo D., Cavallarin L. |title=Effect of chestnut tannin on fermentation quality, proteolysis, and protein rumen degradability of alfalfa silage |journal=J. Dairy Sci. |volume=89 |issue=12 |pages=4736–46 |date=1 December 2006|pmid=17106105 |url=http://jds.fass.org/cgi/pmidlookup?view=long&pmid=17106105 |doi=10.3168/jds.S0022-0302(06)72523-1 }}</ref> Improved fermentability of [[Soybean|soya meal]] nitrogen in the [[rumen]] has also been reported by F. Mathieu and J. P. Jouany (1993).<ref>{{cite journal |doi=10.1051/animres:19930210 |author=Mathieu F., Jouany J. P. |title=Effect of chestnut tannin on the fermentability of soyabean meal nitrogen in the rumen |journal=Ann Zootech |volume=42 |page=127 |year=1993 |issue=2 }}</ref> Studies by S. Gonzalez et al. (2002)<ref>{{cite journal |author=González S., Pabón M. L., Carulla J. |title=Effects of tannins on in vitro ammonia release and dry matter degradation of soybean meal |journal=Arch. Latinoam. Prod. Anim. |volume=10 |issue=2 |pages=97–101 |year=2002}}</ref> on ''in vitro'' ammonia release and dry matter degradation of soybean meal comparing three different types of tannins ([[quebracho tannin|quebracho]], [[acacia]] and chestnut) demonstrated that chestnut tannins are more efficient in protecting soybean meal from ''in vitro'' degradation by rumen bacteria.
 Condensed tannins inhibit herbivore digestion by binding to consumed plant proteins and making them more difficult for animals to digest, and by interfering with protein absorption and digestive enzymes (for more on that topic, see [[plant defense against herbivory]]).
@@ Line 101: / Line 100: @@
 The best-known sources of tannins are tea and wine. See the above articles for more information on the phenolic content of these drinks. Other sources include fruit juices, but not citrus.
-It should be noted that, in contrast to previous reports, coffee has not been found to contain tannins. Tannins were not found in any bean sample, and hydrolysable tannins [[Sensu (taxonomy)|sensu stricto]] were not detected in pulp. The presence of soluble condensed tannins in ''[[Coffea arabica]]'' pulp was confirmed at approximately 1%.<ref>{{cite journal |author=Clifford M.N., Ramirez-Martinez J.R. |title=Tannins in wet-processed coffee beans and coffee pulp |journal=Food Chemistry |volume=40 |issue=2 |pages=191–200 |year=1991 |doi=10.1016/0308-8146(91)90102-T |url=http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6T6R-49NR0X7-1XV&_user=10&_coverDate=12%2F31%2F1991&_rdoc=1&_fmt=high&_orig=search&_sort=d&_docanchor=&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=b61362d5024028d01bdcef6377c13be8}}</ref>
+It should be noted that, in contrast to previous reports, coffee has not been found to contain tannins. Tannins were not found in any bean sample, and hydrolysable tannins [[Sensu (taxonomy)|sensu stricto]] were not detected in pulp. The presence of soluble condensed tannins in ''[[Coffea arabica]]'' pulp was confirmed at approximately 1%.<ref>{{cite journal |author=Clifford M. N., Ramirez-Martinez J. R. |title=Tannins in wet-processed coffee beans and coffee pulp |journal=Food Chemistry |volume=40 |issue=2 |pages=191–200 |year=1991 |doi=10.1016/0308-8146(91)90102-T |url=http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6T6R-49NR0X7-1XV&_user=10&_coverDate=12%2F31%2F1991&_rdoc=1&_fmt=high&_orig=search&_sort=d&_docanchor=&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=b61362d5024028d01bdcef6377c13be8}}</ref>
 ==== Fruit juices ====
@@ Line 107: / Line 106: @@
 ==== Beer ====
-In addition to the [[alpha acid]]s extracted from [[hops]] to provide bitterness in beer, condensed tannins are also present. These originate both from the malt and hops. Especially in Germany, trained brewmasters consider the presence of tannins as a flaw.  In some styles, the presence of this astringency is acceptable or even desired, as, for example, in a [[Flanders red ale]].
+In addition to the [[alpha acid]]s extracted from [[hops]] to provide bitterness in beer, condensed tannins are also present. These originate both from the malt and hops. Especially in Germany, trained brewmasters consider the presence of tannins as a flaw. In some styles, the presence of this astringency is acceptable or even desired, as, for example, in a [[Flanders red ale]].
-In lager type beers, the tannins can form a precipitate with specific haze forming proteins in the [[beer]] resulting in turbidity at low temperature. This chill haze can be prevented by removing part of the tannins or part of the haze forming proteins. Tannins are removed using [[Polyvinylpolypyrrolidone|PVPP]], haze forming proteins by using [[silica]] or tannic acid.<ref>http://www.natural-specialities.com/natural-specialities/PDF/Applications/BR02%20overview%20fact%20sheet%20version%202.1.pdf</ref>
+In lager type beers, the tannins can form a precipitate with specific haze-forming proteins in the [[beer]] resulting in turbidity at low temperature. This chill haze can be prevented by removing part of the tannins or part of the haze-forming proteins. Tannins are removed using [[Polyvinylpolypyrrolidone|PVPP]], haze-forming proteins by using [[silica]] or tannic acid.<ref>http://www.natural-specialities.com/natural-specialities/PDF/Applications/BR02%20overview%20fact%20sheet%20version%202.1.pdf</ref>
 === Food items with tannins ===
@@ Line 120: / Line 119: @@
 ===== Persimmons =====
 [[Image:Persimon.jpg|thumb|right|180px|A persimmon fruit.]]
-Some [[persimmon]]s are highly astringent and therefore inedible when they are not extremely ripe (to be specific, the Korean, American, and Hachiya or Japanese).  This is due to the high level of tannins, and if eaten by humans (and many other animals), the mouth will become completely dry, yet the saliva glands will continue to secrete saliva, which cannot affect the tannin-laced food.{{Clarify|date=October 2009}}
+Some [[persimmon]]s are highly astringent and therefore inedible when they are not extremely ripe (to be specific, the Korean, American, and Hachiya or Japanese). This is due to the high level of tannins, and if eaten by humans (and many other animals), the mouth will become completely dry, yet the saliva glands will continue to secrete saliva, which cannot affect the tannin-laced food.{{Clarify|date=October 2009}}
 ===== Berries =====
 [[Image:Strawberries in white bowl.jpg|thumb|Strawberries in a bowl]]
-Most berries, such as [[cranberry|cranberries]],<ref>{{cite journal |author=Vattem DA, Ghaedian R, Shetty K |title=Enhancing health benefits of berries through phenolic antioxidant enrichment: focus on cranberry |journal=Asia Pac J Clin Nutr |volume=14 |issue=2 |pages=120–30 |year=2005 |pmid=15927928 |url=http://www.nupro.net/science/enhnce%20berry%20phenoli.pdf}}</ref> [[Strawberry|strawberries]] and [[Blueberry|blueberries]],<ref>{{cite journal |author=Puupponen-Pimiä R, Nohynek L, Meier C, ''et al.'' |title=Antimicrobial properties of phenolic compounds from berries |journal=J. Appl. Microbiol. |volume=90 |issue=4 |pages=494–507 |year=2001 |month=April |pmid=11309059 |doi=10.1046/j.1365-2672.2001.01271.x |url=http://www.blackwell-synergy.com/links/doi/10.1046/j.1365-2672.2001.01271.x/abs/}}</ref> contain both hydrolyzable and condensed tannins.
+Most berries, such as [[cranberry|cranberries]],<ref>{{cite journal |author=Vattem D. A., Ghaedian R., Shetty K. |title=Enhancing health benefits of berries through phenolic antioxidant enrichment: focus on cranberry |journal=Asia Pac J Clin Nutr |volume=14 |issue=2 |pages=120–30 |year=2005 |pmid=15927928 |url=http://www.nupro.net/science/enhnce%20berry%20phenoli.pdf}}</ref> [[Strawberry|strawberries]] and [[Blueberry|blueberries]],<ref>{{cite journal |author=Puupponen-Pimiä R., Nohynek L., Meier C., ''et al.'' |title=Antimicrobial properties of phenolic compounds from berries |journal=J. Appl. Microbiol. |volume=90 |issue=4 |pages=494–507 |year=2001 |month=April |pmid=11309059 |doi=10.1046/j.1365-2672.2001.01271.x |url=http://www.blackwell-synergy.com/links/doi/10.1046/j.1365-2672.2001.01271.x/abs/}}</ref> contain both hydrolyzable and condensed tannins.
 ===== Nuts =====
@@ Line 135: / Line 134: @@
 ==== Herbs and spices ====
-[[Clove]]s, [[tarragon]], [[cumin]], [[thyme]], [[vanilla]], and [[cinnamon]] all contain tannins.<ref>Navia, Jeanette. “Could Tannins Explain Classic Migraine Triggers?” 1988</ref>
+[[Clove]]s, [[tarragon]], [[cumin]], [[thyme]], [[vanilla]], and [[cinnamon]] all contain tannins.<ref>Navia, Jeanette. "Could Tannins Explain Classic Migraine Triggers?" 1988</ref>
 ==== Legumes ====
-Most [[legume]]s contain tannins. Red-colored beans contain the most tannins, and white-colored beans have the least. [[Peanut]]s without shells have a very low tannin content. [[Chickpea]]s (garbanzo beans) have a smaller amount of tannins.<ref>{{cite journal |author=Reed JD |title=Nutritional toxicology of tannins and related polyphenols in forage legumes |journal=J. Anim. Sci. |volume=73 |issue=5 |pages=1516–28 |date=1 May 1995|pmid=7665384 |url=http://jas.fass.org/cgi/pmidlookup?view=long&pmid=7665384 }}</ref>
+Most [[legume]]s contain tannins. Red-colored beans contain the most tannins, and white-colored beans have the least. [[Peanut]]s without shells have a very low tannin content. [[Chickpea]]s (garbanzo beans) have a smaller amount of tannins.<ref>{{cite journal |author=Reed J. D. |title=Nutritional toxicology of tannins and related polyphenols in forage legumes |journal=J. Anim. Sci. |volume=73 |issue=5 |pages=1516–28 |date=1 May 1995|pmid=7665384 |url=http://jas.fass.org/cgi/pmidlookup?view=long&pmid=7665384 }}</ref>
 ==== Chocolate ====
-[[Chocolate liquor]] contains about 6% tannins.<ref>{{cite book |author1=Robert L. Wolke |author2=Marlene Parrish |title=What Einstein told his cook 2: the sequel : further adventures in kitchen science |url=http://books.google.com/books?id=jGYMiTMhp9UC&pg=PA433 |date=29 March 2005 |publisher=W. W. Norton & Company |isbn=978-0-393-05869-7 |page=433}}</ref>
+[[Chocolate liquor]] contains about 6% tannins.<ref>{{cite book |author1=Robert L. Wolke |author2=Marlene Parrish |title=What Einstein told his cook 2: the sequel: further adventures in kitchen science |url=http://books.google.com/books?id=jGYMiTMhp9UC&pg=PA433 |date=29 March 2005 |publisher=W. W. Norton & Company |isbn=978-0-393-05869-7 |page=433}}</ref>
 == Health effects of tannins ==
@@ Line 150: / Line 149: @@
 Tannin production began at the beginning of the 19th century with the industrial revolution, to produce tanning material for the need for more leather. Before that time, processes used plant material and were long (up to six months).
-There has been a collapse in the vegetable tannin market in the 1950s-1960s, due to the appearance of [[synthetic tannin]]s, due the scarity of vegetable tannins during World War II. At that time, many small tannin industry sites closed.<ref>[http://webcache.googleusercontent.com/search?q=cache:cFBFXOA8Y0QJ:www.iufro.org/download/file/2480/95/10700-mangrove-ecosystems.doc+%22tannin+market%22&cd=3&hl=fr&ct=clnk&gl=fr&lr=lang_en%7Clang_fr The Status of Mangrove Ecosystems: Trends in the Utilisation and Management of Mangrove Resources. D. Macintosh and S. Zisman]</ref> Vegetable tannins are estimated to be used for the production of 10-20% of the global leather production.
+There has been a collapse in the vegetable tannin market in the 1950s–1960s, due to the appearance of [[synthetic tannin]]s, due the scarity of vegetable tannins during World War II. At that time, many small tannin industry sites closed.<ref>[http://webcache.googleusercontent.com/search?q=cache:cFBFXOA8Y0QJ:www.iufro.org/download/file/2480/95/10700-mangrove-ecosystems.doc+%22tannin+market%22&cd=3&hl=fr&ct=clnk&gl=fr&lr=lang_en%7Clang_fr "The Status of Mangrove Ecosystems: Trends in the Utilisation and Management of Mangrove Resources". D. Macintosh and S. Zisman]</ref> Vegetable tannins are estimated to be used for the production of 10–20% of the global leather production.
 The cost of the final product depends on the method used to extract the tannins, in particular the use of solvents, alkali and other chemicals used (for instance [[Glycerite|glycerin]]). For large quantities, the most cost-effective method is [[hot water extraction]].
@@ Line 164: / Line 163: @@
 Tannins produce different colors with [[ferric chloride]] (either blue, blue black, or green to greenish-black) according to the type of tannin. [[Iron gall ink]] is produced by treating a solution of tannins with [[iron(II) sulfate]].{{Citation needed|date=August 2009}}
-Tannin is a component in a type of industrial [[particleboard]] [[adhesive]] developed jointly by the Tanzania Industrial Research and Development Organization and Forintek Labs Canada.<ref>{{cite journal |doi=10.1016/S0958-9465(02)00072-0 |author=Bisanda E.T.N., Ogola W.O., Tesha J.V. |title=Characterisation of tannin resin blends for particle board applications |journal=Cement and Concrete Composites |volume=25 |issue=6 |pages=593–8 |date=August 2003 |url=http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TWF-47283Y6-1&_user=4296857&_rdoc=1&_fmt=&_orig=search&_sort=d&_docanchor=&view=c&_rerunOrigin=google&_acct=C000012518&_version=1&_urlVersion=0&_userid=4296857&md5=66af73623c18c75f87a46769f57a2496}}</ref> ''[[Pinus radiata]]'' tannins has been investigated for the production of [[Wood glue|wood adhesives]].<ref>{{cite journal |author=Li, Jingge; Maplesden, Frances |title=Commercial production of tannins from radiata pine bark for wood adhesives |journal=IPENZ Transactions |volume=25 |issue=1/EMCh |year=1998 |url=http://www.ipenz.org.nz/ipenz/publications/transactions/Transactions98/emch/7li.PDF |format=PDF}}</ref>
+Tannin is a component in a type of industrial [[particleboard]] [[adhesive]] developed jointly by the Tanzania Industrial Research and Development Organization and Forintek Labs Canada.<ref>{{cite journal |doi=10.1016/S0958-9465(02)00072-0 |author=Bisanda E. T. N., Ogola W. O., Tesha J. V. |title=Characterisation of tannin resin blends for particle board applications |journal=Cement and Concrete Composites |volume=25 |issue=6 |pages=593–8 |date=August 2003 |url=http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TWF-47283Y6-1&_user=4296857&_rdoc=1&_fmt=&_orig=search&_sort=d&_docanchor=&view=c&_rerunOrigin=google&_acct=C000012518&_version=1&_urlVersion=0&_userid=4296857&md5=66af73623c18c75f87a46769f57a2496}}</ref> ''[[Pinus radiata]]'' tannins has been investigated for the production of [[Wood glue|wood adhesives]].<ref>{{cite journal |author=Li, Jingge; Maplesden, Frances |title=Commercial production of tannins from radiata pine bark for wood adhesives |journal=IPENZ Transactions |volume=25 |issue=1/EMCh |year=1998 |url=http://www.ipenz.org.nz/ipenz/publications/transactions/Transactions98/emch/7li.PDF |format=PDF}}</ref>
 [[Condensed tannin]]s, i.e. quebracho tannin, and [[Hydrolyzable tannin]]s, i.e., chestnut tannin, appear to be able to substitute a high proportion of synthetic phenol in phenol-formaldehyde resins for wood [[particleboard]].
@@ Line 170: / Line 169: @@
 Tannins can be used for production of anti-[[corrosion|corrosive]] primer, sold under brand name-Nox Primer for treatment of rusted steel surfaces prior to painting, rust converter to transform oxidized steel into a smooth sealed surface and rust inhibitor.
-The use of [[resin]]s made of tannins has been investigated to remove [[Mercury (element)|mercury]] and [[methylmercury]] from solution.<ref>{{cite journal |author=Torres J., Olivares S., De La Rosa D., Lima L., Martínez F., Munita C.S., Favaro D.I.T. |title=Removal of mercury(II) and methylmercury from solution by tannin adsorbents |journal=Journal of Radioanalytical and Nuclear Chemistry |volume=240 |issue=1 |pages=361–5 |year=1999 |doi=10.1007/BF02349180 |url=http://www.springerlink.com/content/nu6j27t61654t944/}}</ref> Immobilized tannins have been tested to recover [[uranium]] from seawater.<ref>{{cite journal |author=Takashi Sakaguchia, Akira Nakajimaa |title=Recovery of Uranium from Seawater by Immobilized Tannin |journal=Separation Science and Technology |volume=22 |issue=6 |pages=1609–23 |date=June 1987 |doi=10.1080/01496398708058421 |url=http://www.informaworld.com/smpp/content~db=all~content=a762595700}}</ref>
+The use of [[resin]]s made of tannins has been investigated to remove [[Mercury (element)|mercury]] and [[methylmercury]] from solution.<ref>{{cite journal |author=Torres J., Olivares S., De La Rosa D., Lima L., Martínez F., Munita C. S., Favaro D. I. T. |title=Removal of mercury(II) and methylmercury from solution by tannin adsorbents |journal=Journal of Radioanalytical and Nuclear Chemistry |volume=240 |issue=1 |pages=361–5 |year=1999 |doi=10.1007/BF02349180 |url=http://www.springerlink.com/content/nu6j27t61654t944/}}</ref> Immobilized tannins have been tested to recover [[uranium]] from seawater.<ref>{{cite journal |author=Takashi Sakaguchia, Akira Nakajimaa |title=Recovery of Uranium from Seawater by Immobilized Tannin |journal=Separation Science and Technology |volume=22 |issue=6 |pages=1609–23 |date=June 1987 |doi=10.1080/01496398708058421 |url=http://www.informaworld.com/smpp/content~db=all~content=a762595700}}</ref>
 === Medical uses and potential ===
@@ Line 178: / Line 177: @@
 Tannins may also be effective in protecting the kidneys. When incubated with red grape juice and red wines with a high content of condensed tannins, the poliovirus, herpes simplex virus, and various enteric viruses are inactivated.<ref>{{cite book |author=Bajaj, Y. P. S. |title=Medicinal and aromatic plants |publisher=Springer-Verlag |location=Berlin |year=1988 |isbn=0-387-56008-4 |series=Biotechnology in agriculture and forestry |volume=24}}</ref>
-Tannins have shown potential antiviral,<ref>{{cite journal |author=Lü L, Liu SW, Jiang SB, Wu SG |title=Tannin inhibits HIV-1 entry by targeting gp41 |journal=Acta Pharmacol. Sin. |volume=25 |issue=2 |pages=213–8 |year=2004 |month=February |pmid=14769212 }}</ref> antibacterial<ref>{{cite journal |author=Akiyama H, Fujii K, Yamasaki O, Oono T, Iwatsuki K |title=Antibacterial action of several tannins against Staphylococcus aureus |journal=J. Antimicrob. Chemother. |volume=48 |issue=4 |pages=487–91 |year=2001 |month=October |pmid=11581226 |url=http://jac.oxfordjournals.org/cgi/pmidlookup?view=long&pmid=11581226 |doi=10.1093/jac/48.4.487}}</ref> and antiparasitic effects.<ref>{{cite journal |author=Kolodziej H, Kiderlen AF |title=Antileishmanial activity and immune modulatory effects of tannins and related compounds on Leishmania parasitised RAW 264.7 cells |journal=Phytochemistry |volume=66 |issue=17 |pages=2056–71 |year=2005 |month=September |pmid=16153409 |doi=10.1016/j.phytochem.2005.01.011 |url=http://linkinghub.elsevier.com/retrieve/pii/S0031-9422(05)00012-9}}</ref>
+Tannins have shown potential antiviral,<ref>{{cite journal |author=Lü L., Liu S. W., Jiang S. B., Wu S. G. |title=Tannin inhibits HIV-1 entry by targeting gp41 |journal=Acta Pharmacol. Sin. |volume=25 |issue=2 |pages=213–8 |year=2004 |month=February |pmid=14769212 }}</ref> antibacterial<ref>{{cite journal |author=Akiyama H., Fujii K., Yamasaki O., Oono T., Iwatsuki K. |title=Antibacterial action of several tannins against ''Staphylococcus aureus'' |journal=J. Antimicrob. Chemother. |volume=48 |issue=4 |pages=487–91 |year=2001 |month=October |pmid=11581226 |url=http://jac.oxfordjournals.org/cgi/pmidlookup?view=long&pmid=11581226 |doi=10.1093/jac/48.4.487}}</ref> and antiparasitic effects.<ref>{{cite journal |author=Kolodziej H., Kiderlen A. F. |title=Antileishmanial activity and immune modulatory effects of tannins and related compounds on ''Leishmania'' parasitised RAW 264.7 cells |journal=Phytochemistry |volume=66 |issue=17 |pages=2056–71 |year=2005 |month=September |pmid=16153409 |doi=10.1016/j.phytochem.2005.01.011 |url=http://linkinghub.elsevier.com/retrieve/pii/S0031-9422(05)00012-9}}</ref>
 It is believed that tannins isolated from the stem bark of ''[[Myracrodruon urundeuva]]'' may have neuroprotective functions capable of reversing [[6-hydroxydopamine]]-induced toxicity. The plant has shown promise as a potential therapeutic agent, which may be beneficial in patients with neurological disease.<ref name=ahpg >{{cite journal
@@ Line 185: / Line 184: @@
   | authorlink =
   | coauthors =
-  | title = Neuroprotective Actions of Tannins from Myracrodruon urundeuva on 6-Hydroxydopamine-Induced Neuronal Cell Death
+  | title = Neuroprotective Actions of Tannins from ''Myracrodruon urundeuva'' on 6-Hydroxydopamine-Induced Neuronal Cell Death
   | journal = Journal of Herbs, Spices & Medicinal Plants
   | volume = 13
@@ Line 201: / Line 200: @@
   | authorlink =
   | coauthors =
-  | title = Antiinflammatory and antiulcer properties of tannins from Myracrodruon urundeuva Allemão (Anacardiaceae) in Rodents
+  | title = Antiinflammatory and antiulcer properties of tannins from ''Myracrodruon urundeuva'' Allemão (Anacardiaceae) in Rodents
   | journal = Phytotherapy Research
   | volume = 21
@@ Line 214: / Line 213: @@
   | pmid = 17154231
   | last2 = Aquino
-  | first2 = LC
+  | first2 = L. C.
   | last3 = Milach Jr
-  | first3 = AC
+  | first3 = A. C.
   | last4 = Bandeira
-  | first4 = MA
+  | first4 = M. A.
   | last5 = Nobre
-  | first5 = ME
+  | first5 = M. E.
   | last6 = Viana
-  | first6 = GS }}</ref>
+  | first6 = G. S. }}</ref>
 Foods rich in tannins can be used in the treatment of [[HFE hereditary hemochromatosis]], a hereditary disease characterized by excessive absorption of dietary iron, resulting in a pathological increase in total body iron stores.
@@ Line 234: / Line 233: @@
 Following companies are not producers but blenders of tannins for specific applications:
 * AEB group, an Italian company based in Brescia, blends & markets tannins for oenology applications<ref>[http://www.aeb-group.com/or4/or?uid=aeb.main.index&oid=86366 Oenological tannins on www.aeb-group.com]</ref>
-* Enartis, an Italian company based in San Martino, develops and sells oenological tannins<ref>[http://www.enartis.com/eng/index.cfm?mode=prodotti&id=13 Tannins on www.enartis.com]</ref>
+* Enartis, an Italian company based in San Martino, develops and sells oenological tannins.<ref>[http://www.enartis.com/eng/index.cfm?mode=prodotti&id=13 Tannins on www.enartis.com]</ref>
 == See also ==
@@ Line 252: / Line 251: @@
 {{Reflist|30em}}
-*{{cite journal |author=Calvi L, Mwalongo GCJ, Mwingira BA, Riedl B, Shields JA |title=Characterization of Wattle-Tannin-Based Adhesives for Tanzania |journal=Holzforchung |volume=49 |issue=2 |year=1995}}
+*{{cite journal |author=Calvi L., Mwalongo G. C. J., Mwingira B. A., Riedl B., Shields J. A. |title=Characterization of Wattle-Tannin-Based Adhesives for Tanzania |journal=Holzforchung |volume=49 |issue=2 |year=1995}}
 == External links ==