astringent
{{Short description|Chemical compound that tends to shrink or constrict body tissues}}
{{distinguish|Stringent}}
File:Closeup of blackthorn aka sloe aka prunus spinosa sweden 20050924.jpg berries (sloes) give the fruit its sourness.]]
An astringent (sometimes called adstringent) is a chemical that shrinks or constricts body tissues. The word derives from the Latin adstringere, which means "to bind fast". Astringency, the dry, puckering or numbing mouthfeel caused by the tannins{{Cite book |last=Ray |first=P. K. |url=https://books.google.com/books?id=0l2JnsONxlAC |title=Breeding Tropical and Subtropical Fruits |date=2002 |publisher=Springer Science & Business Media |isbn=9783540428558 |language=en |accessdate=2018-12-08}}{{Cite book |last=Joslyn |first=Maynard |url=https://books.google.com/books?id=8b8_f68cyv4C |title=Methods in Food Analysis: Applied to Plant Products |date=2012-12-02 |publisher=Elsevier |isbn=9780323146814 |language=en}} in unripe fruits, lets the fruit mature by deterring eating. Tannins, being a kind of polyphenol, bind salivary proteins and make them precipitate and aggregate,Fennema, Food Chemistry, 4th ed., p. 656.{{cite journal |last1=Breslin |first1=P.A.S. |last2=Gilmore |first2=M.M. |last3=Beauchamp |first3=G.K. |last4=Green |first4=B.G. |date=1993 |title=Psychophysical evidence that oral astringency is a tactile sensation |url=https://academic.oup.com/chemse/article/18/4/405/290466 |journal=Chemical Senses |volume=18 |issue=4 |pages=405–417 |doi=10.1093/chemse/18.4.405|url-access=subscription }}{{cite journal |last1=Bertsch |first1=Pascal |last2=Bergfreund |first2=Jotam |last3=Windhab |first3=Erich J. |last4=Fischer |first4=Peter |date=August 2021 |title=Physiological fluid interfaces: Functional microenvironments, drug delivery targets, and first line of defense |journal=Acta Biomaterialia |volume=130 |pages=32–53 |doi=10.1016/j.actbio.2021.05.051 |pmid=34077806 |s2cid=235323337|doi-access=free |hdl=20.500.11850/498803 |hdl-access=free }} producing a rough, "sandpapery", or dry sensation in the mouth.
Smoking tobacco is also reported to have an astringent effect.{{Cite web |last=McBride |first=Nome |title=Herbal Smoking Mixes |url=https://traditionalroots.org/wp-content/uploads/Herbal-Smoking-Mixtures-NOTES.pdf |access-date=2022-07-20 |website=Traditional Roots Institute}}
In a scientific study, astringency was still detectable by subjects who had local anesthesia applied to their taste nerves, but not when both these and the trigeminal nerves were disabled.{{Cite journal |last1=Jiang |first1=Yue |last2=Gong |first2=Naihua N. |last3=Matsunami |first3=Hiroaki |date=2014 |title=Astringency: A More Stringent Definition |journal=Chemical Senses |volume=39 |issue=6 |pages=467–469 |doi=10.1093/chemse/bju021 |issn=0379-864X |pmc=4064959 |pmid=24860069}}
Uses
In medicine, astringents cause constriction or contraction of mucous membranes and exposed tissues and are often used internally to reduce discharge of blood serum and mucous secretions.{{cite book|last=Brodin|first=Michael|title=The Over-The-Counter Drug Book|url=https://books.google.com/books?id=xyJw_aLOM9sC&pg=PA382|access-date=4 June 2014|year=1998|publisher=Simon and Schuster|isbn=978-0-671-01380-6|page=382}} This can happen with a sore throat, hemorrhages, diarrhea, and peptic ulcers. Externally applied astringents, which cause mild coagulation of skin proteins, dry, harden, and protect the skin.{{cite book|author=Peter A. Ciullo|title=Industrial Minerals and Their Uses: A Handbook and Formulary|url=https://books.google.com/books?id=qQPozu9fWrIC&pg=PA407|access-date=4 June 2014|date=31 December 1996|publisher=William Andrew|isbn=978-0-8155-1808-2|page=407}} People with acne are often advised to use astringents if they have oily skin.[http://brown.edu/Student_Services/Health_Services/Health_Education/common_college_health_issues/acne.php Acne] from http://www.brown.edu Mild astringents relieve such minor skin irritations as those resulting from superficial cuts; allergies; insect bites; anal hemorrhoids;{{cite journal |last1=Acheson |first1=Austin |last2=Scholefield |first2=John |date=2008-02-16 |title=Management of haemorrhoids |journal=BMJ |volume=336 |issue=7640 |pages=380–383 |doi=10.1136/bmj.39465.674745.80 |pmid=18276714 |pmc=2244760 }} and fungal infections such as athlete's foot.{{cite book|last1=Dockery|first1=Gary L.|last2=Crawford|first2=Mary Elizabeth|title=Color Atlas of Foot and Ankle Dermatology|url=https://books.google.com/books?id=wQkML9WQfXsC&pg=PA171|access-date=4 June 2014|year=1999|publisher=Lippincott Williams & Wilkins|isbn=978-0-397-51519-6|page=171}} Redness-reducing eye drops contain an astringent. Use of Goulard's Extract has been discontinued due to lead poisoning.{{cn|date=June 2023}}
Examples
Some common astringents are alum, acacia, sage,{{cite book|last=Dorland|first=W. A. Newman|author-link=Dorland's medical reference works|title=The American illustrated medical dictionary|url=https://books.google.com/books?id=6DG6AAAAIAAJ|access-date=4 June 2014|edition=4th|year=1907|publisher=W.B. Saunders company|location=Philadelphia and London|pages=14, 39, 635}} yarrow,{{cite book|last=Grieve|first=Maud|author-link=Maud Grieve|title=A Modern Herbal: The Medicinal, Culinary, Cosmetic and Economic Properties, Cultivation and Folk-lore of Herbs, Grasses, Fungi, Shrubs, & Trees with All Their Modern Scientific Uses|url=https://books.google.com/books?id=REy8Yiyf2HEC&pg=PA863|access-date=4 June 2014|date=1 June 1971|publisher=Dover Publications|isbn=978-0-486-22799-3|pages=863–864}} witch hazel, bayberry, distilled vinegar, very cold water, and rubbing alcohol. Astringent preparations include silver nitrate, potassium permanganate, zinc oxide, zinc sulfate, Burow's solution, tincture of benzoin, and such vegetable substances as tannic and gallic acids. Balaustines are the red rose-like flowers of the pomegranate, which are very bitter to the taste. In medicine, their dried form has been used as an astringent.[http://digicoll.library.wisc.edu/cgi-bin/HistSciTech/HistSciTech-idx?type=turn&entity=HistSciTech000900240228&isize=L History of Science: Cyclopædia, or, An universal dictionary of arts and sciences…] Some metal salts and acids have also been used as astringents.{{cite book|last=Gregory|first=James|title=Conspectus medicinae theoretic medicine; in two parts: Part I. Containing physiology and pathology. Part II. Containing therapeutics|url=https://archive.org/details/conspectusmedic00greggoog|access-date=4 June 2014|edition=2nd|year=1833|publisher=Stirling & Kenneg|location=London|pages=[https://archive.org/details/conspectusmedic00greggoog/page/n269 255]–256}}
Calamine lotion, witch hazel, and yerba mansa, are astringents,[http://nathistoc.bio.uci.edu/Plants%20of%20Upper%20Newport%20Bay%20%28Robert%20De%20Ruff%29/Saururaceae/Anemopsis%20californica.htm Anemopsis californica] from University of California, Irvine as are the powdered leaves of the myrtle.{{Cite journal |last=Borg |first=John |date=1927 |title=Descriptive flora of the Maltese Islands |url=https://scholar.google.com/scholar_lookup?title=Descriptive+flora+of+the+Maltese+Islands&author=Borg%2C+John&publication_year=1927 |language=English}} Ripe fruits and fruit parts including blackthorn (sloe berries), Aronia chokeberry, chokecherry, bird cherry, rhubarb, quince, jabuticaba and persimmon fruits (especially when unripe), banana skins (or unripe bananas), cashew fruits and acorns are astringent.{{Cite book |last1=Choi |first1=Nak-Eon |url=https://books.google.com/books?id=zV64BQAAQBAJ |title=How Flavor Works: The Science of Taste and Aroma |last2=Han |first2=Jung H. |date=2014-12-03 |publisher=John Wiley & Sons |isbn=9781118865453 |language=en}} Citrus fruits, like lemons, are somewhat astringent. The tannins in some teas, coffee, and red grape wines like Cabernet Sauvignon and Merlot produce mild astringency.{{cn|date=June 2023}} Astringency is used in classifications of white wine.
References
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