Grapefruit
From Wikipedia, the free encyclopedia
The grapefruit (Citrus × paradisi) is a subtropical citrus tree known for its sour to semi-sweet fruit, an 18th-century hybrid first bred in Barbados. When found, it was named the "forbidden fruit"; and it has also been misidentified with the pomelo or shaddock (C. maxima), one of the parents of this hybrid, the other being sweet orange (C. × sinensis).
Grapefruit | |
---|---|
Grapefruit, hybrid citrus. | |
Scientific classification | |
Kingdom: | Plantae |
(unranked): | Angiosperms |
(unranked): | Eudicots |
(unranked): | Rosids |
Order: | Sapindales |
Family: | Rutaceae |
Genus: | Citrus |
Species: | C. × paradisi |
Binomial name | |
Citrus × paradisi Macfad. |
Description
Grapefruit growing in the grape-like clusters from which their name derives. |
History
1750 Engraving of The Forbidden Fruit Tree by Georg Dionysius Ehret |
FORBIDDEN-FRUIT-TREE
The Trunk, Leaves, and Flowers of this Tree, very much resemble
those of the Orange-tree.
The Fruit, when ripe, is something longer and larger than the largest
Orange; and exceeds, in the Delicacy of its Taste, the Fruit of every
Tree in this or any of our neighbouring Islands.
It hath somewhat of the Taste of a Shaddock; but far exceeds that, as
well as the best Orange, in its delicious Taste and Flavour.
The Trunk, Leaves, and Flowers of this Tree, very much resemble
those of the Orange-tree.
The Fruit, when ripe, is something longer and larger than the largest
Orange; and exceeds, in the Delicacy of its Taste, the Fruit of every
Tree in this or any of our neighbouring Islands.
It hath somewhat of the Taste of a Shaddock; but far exceeds that, as
well as the best Orange, in its delicious Taste and Flavour.
—Description from Hughes' 1750 Natural History of Barbados.
The grapefruit was brought to Florida by Count Odet Philippe in 1823 in what is now known as Safety Harbor. Further crosses have produced the tangelo (1905), the Minneola tangelo (1931), and the oroblanco (1984).
The grapefruit was known as the shaddock or shattuck until the 19th century. 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 1940s. This led to the official name being altered to Citrus × paradisi, the "×" identifying its hybrid origin.
Kimball Chase Atwood |
Ruby Red
The 1929 Ruby Red patent was associated with real commercial success, which came after the discovery of a red grapefruit growing on a pink variety. The Red grapefruit, starting with the Ruby Red, has even become a symbolic fruit of Texas, where white "inferior" grapefruit were eliminated and only red grapefruit were grown for decades.[citation needed] Using radiation to trigger mutations, new varieties were developed to retain the red tones which typically faded to pink, the Rio Red variety is the current (2007) Texas grapefruit with registered trademarks Rio Star and Ruby-Sweet, also sometimes promoted as "Reddest" and "Texas Choice". The Rio Red is a mutation bred variety which was developed by treatment of bud sticks with thermal neutrons. Its improved attributes of mutant variety are fruit and juice color, deeper red, and wide adaptation.Star Ruby
The Star Ruby is the darkest of the red varieties. Developed from an irradiated Hudson grapefruit, it has found limited commercial success because it is more difficult to grow than other varieties.Varieties
The varieties of Texas and Florida grapefruit include: Oro Blanco, Ruby Red, Pink, Thompson, White Marsh, Flame, Star Ruby, Duncan, and Pummelo HB.Production
Grapefruit and pomelo output in 2005 |
Top ten grapefruit (inc. pomelos) producers — 2007 | ||||
---|---|---|---|---|
Country | Production (metric tons) | Footnote | ||
United States | 1,580,000 | |||
People's Republic of China | 547,000 | F | ||
South Africa | 430,000 | F | ||
Mexico | 390,000 | F | ||
Syria | 290,000 | F | ||
Israel | 245,000 | * | ||
Turkey | 181,923 | |||
India | 178,000 | F | ||
Argentina | 176,000 | F | ||
Cuba | 175,000 | F | ||
World | 5060000 | A | ||
No symbol = official figure, P =
official figure, F = FAO estimate, * = Unofficial/Semi-official/mirror
data, C = Calculated figure A = Aggregate (may include official,
semi-official or estimates); Source: Food And Agricultural Organization of United Nations: Economic And Social Department: The Statistical Division |
Colors and flavors
Grapefruit mercaptan |
Drug interactions
grapefruit interacts with the effects of some drugs |
This white grapefruit is cushioned with a thick mesocarp layer |
Grapefruit juice contains furanocoumarins. Furanocoumarins irreversibly inhibit a cytochrome P450 metabolizing enzyme called CYP3A4, as stated above. CYP3A4 is a metabolizing enzyme for almost 50% of drugs, and is found in the liver and small intestinal epithelial cells. As a result, many drugs are impacted by consumption of grapefruit juice. When the metabolizing enzyme is inhibited, less of the drug will be metabolized by it in the epithelial cells. A decrease in drug metabolism means more of the original form of the drug could pass unchanged to systemic blood circulation. An unexpected high dose of the drug in the blood could lead to fatal drug toxicity.
The furanocoumarins found in grapefruit juice are natural chemicals. Thus, they are present in all forms of the fruit, including freshly squeezed juice, frozen concentrate, and whole fruit. All these forms of the grapefruit juice have the potential to limit the metabolizing activity of CYP3A4. One whole grapefruit, or a glass of 200 mL of grapefruit juice can cause drug overdose toxicity.
According to a review done by the Canadian Medical Association, there is an increase in the number of potential drugs that can interact with grapefruit juice. From 2008 to 2012, the percentage of drugs that interact with grapefruit juice and cause serious harmful effects (gastrointestinal bleeding, nephrotoxicity) has increased from 17 to 43 percent.
The interaction between grapefruit juice and other medication depends on the drug, and not the class of the drug. Drugs that interact with grapefruit juice share 3 common features: they are taken orally, normally only a small amount enters systemic blood circulation, and they are metabolized by CYP3A4.
Inhibition of the CPA 3A4 enzyme is irreversible and lasts a significant period of time. It takes around 24 hours to regain 50% of the enzyme activity and it can take 72 hours for the enzyme to completely return to activity. For this reason, simply separating grapefruit consumption and medication taken daily does not avoid the interaction. For medications that interact due to inhibition of OATP (organic anion-transporting polypeptides), a relative short period of time is needed to avoid this interaction. A 4-hour interval between grapefruit consumption and the medication should suffice. For drugs recently sold on the market, drugs have information pages (monographs) that provide information on any potential interaction between a medication and grapefruit juice. Because there is a growing number of medications that are known to interact with grapefruit juice, patients should consult a pharmacist or physician before planning to take grapefruit juice with their medications.
Grapefruit juice may be the first drug-interacting fruit juice documented, but apple and orange juices have been also implicated in interfering with etoposide, a chemotherapy drug, some beta blocker drugs used to treat high blood pressure, and cyclosporine, taken by transplant patients to prevent rejection of their new organs. Some citrus-based carbonated beverages (e.g., “Sun Drop”) also contain enough grapefruit juice to cause drug interactions, particularly in patients taking cyclosporine.
Unlike other fruits, grapefruit contains a large amount of naringin, and it can take up to 72 hours before the effects of the naringin on the CYP3A4 enzyme are seen. This is particularly problematic due to the fact that only 4 oz of grapefruit contain enough naringin to inhibit the metabolism of substrates of CYP3A4.
Nutritional properties
Nutritional value per 100 g (3.5 oz) | |
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Energy | 138 kJ (33 kcal) |
8.41 g
|
|
Sugars | 7.31 g |
Dietary fiber | 1.1 g |
0.10 g
|
|
0.69 g
|
|
Vitamins | |
Thiamine (B1) |
(3%)
0.037 mg |
Riboflavin (B2) |
(2%)
0.020 mg |
Niacin (B3) |
(2%)
0.269 mg |
(6%)
0.283 mg |
|
Vitamin B6 |
(3%)
0.043 mg |
Folate (B9) |
(3%)
10 μg |
Choline |
(2%)
7.7 mg |
Vitamin C |
(40%)
33.3 mg |
Vitamin E |
(1%)
0.13 mg |
Trace metals | |
Calcium |
(1%)
12 mg |
Iron |
(0%)
0.06 mg |
Magnesium |
(3%)
9 mg |
Manganese |
(1%)
0.013 mg |
Phosphorus |
(1%)
8 mg |
Potassium |
(3%)
148 mg |
Zinc |
(1%)
0.07 mg |
Other constituents | |
Water | 90.48 g |
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Percentages are roughly approximated using US recommendations for adults. Source: USDA Nutrient Database |
Grapefruit seed extract (GSE) has been shown to have strong antimicrobial properties against fungi. It is also believed to have antimicrobial properties for bacteria, however there are no known studies that demonstrate its efficacy. Additionally, although GSE is promoted as a highly effective plant-based preservative by some natural personal care manufacturers, studies have shown that the apparent antimicrobial activity associated with GSE preparations is merely due to contamination with synthetic preservatives.
Since grapefruit juice is known to inhibit enzymes necessary for the clearance of some drugs and hormones, some have hypothesized that grapefruit juice may play an indirect role in the development of hormone-dependent cancers. A 2007 study found a correlation between eating a quarter of grapefruit daily and a 30% increase in risk for breast cancer in post-menopausal women. The study points to the inhibition of CYP3A4 enzyme by grapefruit, which metabolizes estrogen. However, a 2008 study has shown that grapefruit consumption does not increase breast cancer risk and found a significant decrease in breast cancer risk with greater intake of grapefruit in women who never used hormone therapy.
There is a popular myth that grapefruits contain high amounts of spermidine, a simple polyamine that may be related to aging. The myth probably relies on the confusion between spermidine and putrescine. While citrus fruits show high amounts of putrescine, they contain very little spermidine.