Grapefruit

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{{Taxobox | color = lightgreen | name = Grapefruit | image = Grapefruit_700x490.jpg | image_width = 250px | image_caption = A basket of grapefruit | regnum = Plantae | divisio = Magnoliophyta | classis = Magnoliopsida | subclassis = Rosidae | ordo = Sapindales | familia = Rutaceae | genus = Citrus | species = C. paradisi | binomial = Citrus paradisi | binomial_authority = Macfad. }}

This article is about the citrus fruit. For the Sixties pop band, see Grapefruit (band)

The grapefruit is a sub-tropical citrus tree grown for its fruit, which are also known as grapefruit.

The evergreen tree is usually found at around 5-6 m tall, although it can reach 13-15 m. The leaves are dark green, long (up to 150 cm) and thin. It produces 5 cm white four-petalled flowers. The fruit is yellow-skinned, largely oblate and ranges in diameter from 10-15 cm and has an acidic yellow segmented pulp. The numerous cultivars include the white grapefruit and the red, of which the 1929 US Ruby Red (of the Redblush variety) has a patent. The fruit has only become popular from the late 19th century; before that it was only grown as an ornamental plant. The US quickly became a major producer of the fruit, with orchards in Florida and Texas. In Spanish the fruit is known as toronja or pomelo.

The fruit was discovered in the 1750s, probably in Barbados; currently the grapefruit is said to be one of the "Seven Wonders of Barbados" [1]. It had developed as a hybrid of the pomelo (Citrus maxima) with the sweet orange (Citrus sinensis), though it is rather closer to the first than the second. Further crosses have produced the tangelo (1905), the minneola (1931) and the sweetie (1984).

The grapefruit was known as the shaddock until the 1800s. Its current name alludes to clusters of the fruit on the tree, which often appear similar to grapes. Botanically, it was not distinguished from the pomelo until the 1830s, when it was given the name Citrus paradisi. Its true origins were not determined until the 1950s. This led to the official name being altered to Citrus × paradisi.

Grapefruit can have a number of interactions with drugs, often increasing the effective potency of compounds. Grapefruit contains naringin and bergamottin, which inhibit the cytochrome P450 isoform CYP3A4 in the liver. It is via inhibition of this enzyme that grapefruit increases the effects of buspirone (Buspar), caffeine, simvastatin, terfenadine, felodipine, nifedipine, verapamil, estradiol, midazolam, tacrolimus, dextromethorphan (significant only at recreational doses), benzodiazepines and cyclosporine A. This effect was responsible for a number of deaths due to overdosing on medication, which led to its discovery. Grapefruit seed extract has been claimed to be a strong antimicrobial with proven activity against bacteria and fungi. However, studies have shown that this may be due to contamination with synthetic preservatives, and that grapefruit seed extract has no natural antimicrobial properties. The efficacy of grapefruit seed extract as an antimicrobial is not well established. [2] [3] [4] There is also some evidence that grapefruit seed extract has antioxidant properties. [5] [6]

Grapefruit forms a core part of the "grapefruit diet", the theory being that the fruit's low glycemic index is able to help the body's metabolism burn fat.

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References

Takeoka, G.R., Dao, L.T., Wong, R.Y., Harden L.A. Identification of benzalkonium chloride in commercial grapefruit seed extracts. J Agric Food Chem. 2005 53(19):7630–6
von Woedtke, T., Schlüter, B., Pflegel, P., Lindequist, U.; Jülich, W.-D. Aspects of the antimicrobial efficacy of grapefruit seed extract and its relation to preservative substances contained. Pharmazie 1999 54:452–456.
Sakamoto, S., Sato, K., Maitani, T., Yamada, T. Analysis of components in natural food additive “grapefruit seed extract” by HPLC and LC/MS. Bull. Natl. Inst. Health Sci. 1996, 114:38–42.
Ceranowicz, P., Dembinski, A., Dembinski, M., Konturek, S. J., Kusnierz-Cabala, B., Naskalski, J. W., Pawlik, W.W., Warzecha, Z. Extract of Grapefruit-Seed Reduces Acute Pancreatitis Induced by Ischemia/Reperfusion in Rats; Possible Implication of Tissue Antioxidants. Department of Physiology, Jagiellonian University Medical School, Cracow, Poland 2004.
Armando, C., Maythe, S., Beatriz, N. P. Antioxidant activity of grapefruit seed extract on vegetable oils. Journal of the Science of Food and Agriculture 1998, 77:463-467.