Shea butter
Shea butter is a slightly yellowish or ivory-colored fat extracted from the nut of the African shea tree (Vitellaria paradoxa).[1] Shea Butter is also referred to as Ori.[2] It is widely used in cosmetics as a moisturizer, salve or lotion. Shea butter is edible and is used in food preparation in Africa.[3] Occasionally the chocolate industry uses shea butter mixed with other oils, as a substitute for cocoa butter, although the taste is different.[4][5]
The English word "shea" comes from s'í, the tree's name in the Bamana language of Mali.[6] The French name karité comes from ghariti, its equivalent in the Wolof language of Senegal.[citation needed]
Butter extraction and refining
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The traditional method of preparing unrefined shea butter consists of the following steps:
- Separating/cracking: The outer pulp of the fruit is removed. When dry, the nut, which is the source of shea butter, must be separated from the outer shell. This is a social activity, traditionally done by Women Elders and young girls who sit on the ground and break the shells with small rocks.
- Crushing: To make the shea nuts into butter, they must be crushed. Traditionally, this is done with mortars and pestles. It requires lifting the pestles and grinding the nuts into the mortars to crush the nuts so they can be roasted.
- Roasting: The crushed nuts are then roasted in huge pots over open, wood fires. The pots must be stirred constantly with wooden paddles so the butter does not burn. The butter is heavy and stirring it is hot, smoky work, done under the sun. This is where the slight, smoky smell of traditional shea butter originates.
- Grinding: The roasted shea nuts are ground into a smoother paste, water is gradually added and the paste is mixed well by hand.
- Separating the oils: The paste is kneaded by hand in large basins and water is gradually added to help separate out the butter oils. As they float to the top, the butter oils, which are in a curd state, are removed and excess water squeezed out. The butter oil curds are then melted in large open pots over slow fires. A period of slow boiling will remove any remaining water, by evaporation.
- Collecting and shaping: The shea butter, which is creamy or golden yellow at this point, is ladled from the top of the pots and put in cool places to harden. Then it is formed into balls.
Industrially, a mechanical sheller such as the Universal Nut Sheller may be used, although controversy over its usability with shea nuts is reported in that article. The refined butter may be extracted with chemicals such as hexane, or by clay filtering.
Composition and properties
Shea butter extract is a complex fat that contains, besides many nonsaponifiable components (substances that cannot be fully converted into soap by treatment with alkali), the following fatty acids:oleic acid (40-60%), stearic acid (20-50%), linoleic acid (3-11%), palmitic acid (2-9%), linolenic acid(<1%) and arachidic acid(<1%).[7]
Shea butter melts at body temperature. Proponents of its use for skin care maintain that it absorbs rapidly into the skin without leaving a greasy feeling[citation needed].
Uses
Shea butter is mainly used in cosmetics, such as lip gloss moisturizer creams and emulsions, and hair conditioners for dry and brittle hair.[citation needed] It is also used by soap makers, typically in small amounts (5-7% of the oils in the recipe), because of its property of leaving a small amount of oil in the soap.[citation needed]
In Africa, shea butter is used for cooking oil, as a waterproofing wax, for hairdressing, for candle-making, and also as an ingredient in medicinal ointments. It is also used by makers of traditional African percussion instruments to increase the durability of wood (such as carved djembe shells), dried calabash gourds, and leather tuning straps.[citation needed]
Medicinal
Shea butter is used as a base for medicinal ointments. Some of the isolated chemical constituents are reported to have anti-inflammatory, emollient and humectant properties.[8] Shea butter has been used as a sunblocking lotion and has a limited capacity to absorb ultraviolet radiation. [4]
In Ghana, shea butter, locally known as nkuto (Akan) or nku (Ga) is used as lotion to protect the skin during the dry Harmattan season.[citation needed]
In Nigeria shea butter is used for the management of sinusitis and relief of nasal congestion.[9] It is also massaged into joints and other parts of the body where pain is experienced.[citation needed]
Classification
Some companies[who?] have suggested a classification system for shea butter separating it into five grades: A (raw or unrefined, extracted using water), B (refined), C (highly refined and extracted with solvents such as hexane), D (lowest uncontaminated grade), E (with contaminants). Commercial grades are A, B, C. The color of raw (grade A) butter ranges from cream (like whipped butter) to grayish yellow, and it has a nutty aroma which is removed in the other grades. Grade C is pure white [citation needed] While the level of vitamin content can be affected by refining, up to 95% of vitamin content can remain in refined grades (i.e. grade C) of shea butter while reducing contamination levels to non-detectable levels.[citation needed]
See also
- Shea nut and butter production in Burkina Faso
- Shea Yeleen, a social enterprise that empowers and trains women-owned shea butter cooperatives
References
- ^ Alfred Thomas (2002). "Fats and Fatty Oils". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a10_173.
- ^ http://skinglowbykimmarie.com/blog/?page_id=2
- ^ http://books.nap.edu/openbook.php?record_id=11763&page=303
- ^ a b http://www.fao.org/docrep/008/y5918e/y5918e11.htm
- ^ Fold, N. 2000. A matter of good taste? Quality and the construction of standards for chocolate in the European Union. Cahiers d’Economie et Sociologie Rurales, 55/56: 92–110 http://www.inra.fr/sae2/publications/cahiers/pdf/fold.pdf
- ^ "Reference.com Dictionary Entry". Retrieved 25 August 2012.
- ^ Davrieux, F., Allal, F., Piombo, G., Kelly, B., Okulo, J.B., Thiam, M., Diallo, O.B. & Bouvet, J.-M. (2010) Near Infrared Spectroscopy for High-Throughput Characterization of Shea Tree (Vitellaria paradoxa) Nut Fat Profiles. Journal of Agricultural and Food Chemistry, 58, 7811-7819.
- ^ Akihisa, T; Kojima, N; Kikuchi, T; Yasukawa, K; Tokuda, H; t Masters, E; Manosroi, A; Manosroi, J (2010). "Anti-inflammatory and chemopreventive effects of triterpene cinnamates and acetates from shea fat". Journal of oleo science. 59 (6): 273–80. PMID 20484832.
- ^ Tella, A, Br (1979). "Preliminary studies on nasal decongestant activity from the seed of the shea butter tree, Butyrospermum parkii". J Clin Pharmacol. 7 (5): 495–497.
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