Both beaver sexes have a pair of castor sacs and a pair of anal glands, located in two cavities under the skin between the pelvis and the base of the tail. The castor sacs are not true glands (endocrine or exocrine) on a cellular level, hence references to these structures as preputial glands, castor glands, or scent glands are misnomers.
It is extracted with alcohol from the dried and crushed castor sacs for use as a tincture in some perfumes and, rarely, as a food additive.
North American beavers at the Smithsonian National Zoo, in Washington, D.C.
In perfumery, the term castoreum refers to the resinoid extract resulting from the dried and alcohol tinctured beaver castor. The dried beaver castor sacs are generally aged for two or more years to mellow.
Castoreum is largely used for its note suggesting leather, typically compounded with other ingredients, including top, middle, and base notes. Some classic perfumes incorporating castoreum are Emeraude, Chanel Antaeus, Cuir de Russie, Magie Noire, Lancôme Caractère, Hechter Madame, Givenchy III, Shalimar, and many "leather" themed compositions.
In food
In the United States, the Food and Drug Administration lists castoreum extract as a generally recognized as safe (GRAS) food additive. In 1965, the Flavor and Extract Manufacturers Association's GRAS program (FEMA 2261 and 2262) added castoreum extract and castoreum liquid. Historically, compounds isolated from castoreum were used in strawberry and raspberry flavorings and vanilla substitutes, but at present, the annual industry consumption is very low, around 100 kilograms (220lb), whereas vanillin is over 1.2millionkg (2.6millionlb) annually.
Castoreum has been traditionally used in Sweden for flavoring a variety of snaps commonly referred to as Bäverhojt (lit.'beaver shout').
Other
Castoreum was also considered as an ingredient for the flavor and odor of cigarettes.
Medieval beekeepers used castoreum to increase honey production.
Related animal products
Taxea, a secretion of the badger's subcaudal glands comparable in its medicinal use to the better-known castoreum
Hyraceum, the petrified and rock-like excrement composed of urine and feces excreted by the Cape hyrax (Procavia capensis), and a sought-after material that has been used in traditional South African medicine and perfumery
↑Svendsen, G.E., Huntsman, W.D, "A field Assay of Beaver Castoreum and Some of its Components". American Midland Naturalist, Vol. 120, No. 1 (Jul. 1988), pp. 144–149, University of Notre Dame. JSTOR2425894.
↑Pheromonal activity of single castoreum constituents in beaver, Castor canadensis., Müller-Schwarze, D and Houlihan, P.W., Journal of Chemical Ecology, April 1991, Volume 17, Number 4, Springer Netherlands, doi:10.1007/BF00994195
↑Neutral compounds from male castoreum of North American beaver, Castor canadensis. Rong Tang, Francis X. Webster, Dietland Müller-Schwarze, Journal of Chemical Ecology, November 1995, Volume 21, Issue 11, pages 1745–1762, doi:10.1007/BF02033674
12The Beaver: Its Life and Impact. Dietland Muller-Schwarze, 2003, page 43 (book at Google Books)
↑Stereoselective synthesis of enantiomerically pure nupharamine alkaloids from castoreum. Stoye A, Quandt G, Brunnhöfer B, Kapatsina E, Baron J, Fischer A, Weymann M and Kunz H, Angew Chem Int Ed Engl., 2009, volume 48, issue 12, pages 2228–2230, doi:10.1002/anie.200805606
↑Zur Kenntnis der stickstoffhaltigen Inhaltsstoffe von Castoreum. B. Maurer and G. Ohloff, Helvetica Chimica Acta, 2 June 1976, Volume 59, Issue 4, pages 1169–1185, doi:10.1002/hlca.19760590420
↑cis-Cyclohexane-1,2-diol in the beaver gland. Z. Valenta, A. Khaleque, M. H. Rashid, Experientia, 1961, Volume 17, Issue 3, page 130, doi:10.1007/BF02160827