The grapefruit (
Citrus × paradisi) is a subtropical citrus tree known
for its sour to semi-sweet, somewhat bitter fruit.
Grapefruit is a
hybrid originating in
Barbados as an accidental cross between two
introduced species, sweet orange (C. sinensis) and pomelo or shaddock
(C. maxima), both of which were introduced from Asia in the
seventeenth century. When found, it was named the "forbidden
fruit"; and frequently, it has been misidentified with the
The grapefruit's name alludes to clusters of the fruit on the tree,
which often appear similar to that of grapes.
2.1 Ruby Red
2.2 Star Ruby
5 Colors and flavors
6 Drug interactions
7 Nutritional properties
9 Other uses
11 See also
13 External links
Grapefruit growing in the grape-like clusters from which their name
The evergreen grapefruit trees usually grow to around 5–6 meters
(16–20 ft) tall, although they may reach 13–15 m
(43–49 ft). The leaves are glossy, dark green, long (up to 15
centimeters (5.9 in)), and thin. It produces 5 cm
(2 in) white four-petaled flowers. The fruit is yellow-orange
skinned and generally, an oblate spheroid in shape; it ranges in
diameter from 10–15 cm (3.9–5.9 in). The flesh is
segmented and acidic, varying in color depending on the cultivars,
which include white, pink, and red pulps of varying sweetness
(generally, the redder varieties are the sweetest). The 1929 U.S. Ruby
Red (of the Redblush variety) has the first grapefruit patent.
Citrus taxonomy § Oranges
The genetic origin of the grapefruit is a hybrid mix. One ancestor
of the grapefruit was the Jamaican sweet orange (
itself an ancient hybrid of Asian origin; the other was the Indonesian
pomelo (C. maxima). One story of the fruit's origin is that a certain
"Captain Shaddock" brought pomelo seeds to Jamaica and bred the
first fruit, however, it probably originated as a naturally
occurring hybrid between the two plants some time after they had been
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 hybrid fruit, then called "the forbidden fruit", was first
documented in 1750 by a Welshman, Rev. Griffith Hughes, who described
Barbados in The Natural History of Barbados.
Currently, the grapefruit is said to be one of the "Seven Wonders of
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
The grapefruit was known as the shaddock or shattuck until the
nineteenth century. Its current name alludes to clusters of the
fruit on the tree, which often appear similar to that of 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
Citrus × paradisi, the "×" identifying its hybrid
An early pioneer in the American citrus industry was Kimball Atwood, a
wealthy entrepreneur who founded the Atwood
Grapefruit Company in the
late nineteenth century. The Atwood Grove became the largest
grapefruit grove in the world, with a yearly output of 80,000 boxes of
fruit. It was there that pink grapefruit was first discovered in
The 1929 Ruby
Red patent was associated with real commercial success,
which came after the discovery of a red grapefruit growing on a pink
Red grapefruit, starting with the Ruby Red, has even
become a symbolic fruit of Texas, where white 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.
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 that 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.
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
The varieties of
Texas and Florida grapefruit include: Oro Blanco,
Ruby Red, Pink, Thompson,
White Marsh, Flame, Star Ruby, Duncan, and
1750 Engraving of The Forbidden
Fruit Tree by Georg Dionysius Ehret
Grapefruit in growth
Half peeled 'Indian' cultivar
China is the top producer of grapefruit and pomelo. It is followed by
United States and Mexico.
Top eleven grapefruit (inc. pomelos) producers — 2012
Production (metric tons)
People's Republic of China
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 comes in many varieties. One way to differentiate between
varieties is by the flesh color of fruit they produce. The most
popular varieties currently cultivated are red, white, and pink hues,
referring to the internal pulp color of the fruit. The family of
flavors range from highly acidic and somewhat sour, to sweet and
Grapefruit mercaptan, a sulfur-containing terpene, is one of
the substances which has a strong influence on the taste and odor of
grapefruit, compared with other citrus fruits.
Main article: Grapefruit–drug interactions
Grapefruit and grapefruit juice have been found to interact with
numerous drugs and in many cases, to result in adverse direct and/or
side effects (if dosage is not carefully adjusted.)
This happens in two very different ways. In the first, the effect is
from bergamottin, a natural furanocoumarin in both grapefruit flesh
and peel that inhibits the
CYP3A4 enzyme, (among others from the P450
enzyme family responsible for metabolizing 90% of drugs). The action
CYP3A4 enzyme itself is to metabolize many medications.
If the drug's breakdown for removal is lessened, then the level of the
drug in the blood may become too high or stay too long, leading to
adverse effects. On the other hand, some drugs must be broken down
to become active, and inhibiting
CYP3A4 may lead to reduced drug
The other effect is that grapefruit can block the absorption of drugs
in the intestine. If the drug is not absorbed, then not enough of
it is in the blood to have a therapeutic effect. Each affected
drug has either a specific increase of effect or decrease.
One whole grapefruit, or a glass of 200 mL
(6.8 US fl oz) of grapefruit juice may cause drug
overdose toxicity. Typically, drugs that are incompatible with
grapefruit are so labeled on the container or package insert.
People taking drugs should ask their health care provider or
pharmacist questions about grapefruit and drug interactions.
Grapefruit, raw, white, all areas
Nutritional value per 100 g (3.5 oz)
138 kJ (33 kcal)
Pantothenic acid (B5)
Link to USDA Database entry
μg = micrograms • mg = milligrams
IU = International units
Percentages are roughly approximated using US recommendations for
Source: USDA Nutrient Database
Grapefruit is a rich source of vitamin C (>20% of the Daily Value,
DV in a 100 gram serving), contains the fiber pectin, and
the pink and red hues contain the beneficial antioxidant
lycopene. Studies have shown grapefruit helps lower
cholesterol, and there is evidence that the seeds have
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.
Although grapefruit seed extract (GSE) is promoted as a 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 such as parabens.
There is a popular myth that grapefruits contain high amounts of
spermidine, a simple polyamine that may be related to aging.[citation
needed] The myth probably relies on the confusion between spermidine
and putrescine. While citrus fruits show high amounts of putrescine,
they contain very little spermidine.
Grapefruit juice contains about half the citric acid of lime or lemon
juice (which contain about 47 g/l), and about two-and-a-half
times the amount of citric acid found in orange juice.
In Costa Rica, especially in Atenas, grapefruit are often cooked to
remove their sourness, rendering them as sweets; they are also stuffed
with dulce de leche, resulting in a dessert called toronja rellena
(stuffed grapefruit). In Haiti, grapefruit is used
primarily for its juice (jus de Chadèque), but also is used to make
jam (confiture de Chadèque).
Grapefruit has also been investigated in cancer medicine
pharmacodynamics. Its inhibiting effect on the metabolism of some
drugs may allow smaller doses to be used, which can help to reduce
Grapefruit is a pummelo backcross, a hybrid of pummelo × sweet
orange, with sweet orange itself being a pummelo × mandarin hybrid.
The grapefruit is a parent to many hybrids:
Tangelo is any hybrid of a tangerine and either a pomelo or a
'Minneola': Duncan grapefruit × Dancy tangerine
'Orlando' (formerly 'Take'): Bowen grapefruit × Dancy
Fairchild is a
Clementine × Orlando hybrid
'Seminole': Bowen grapefruit × Dancy tangerine
'Thornton': tangerine × grapefruit, unspecified
'Ugli': mandarin × grapefruit, probable (wild seedling)
'Nova' is a second-generation hybrid:
Clementine × Orlando tangelo
Melogold grapefruits are hybrids between pummelo
Citrus maxima) and the grapefruit
The grapefruit's cousins include:
Common sweet orange: pummelo × mandarin hybrid
Bitter orange: a different pummelo × mandarin hybrid
Mandelos: pummelo × mandarine (
Hyuganatsu may also be a pumelo hybrid
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Barbados (1750) by
Rev. Griffith Hughes. This accords with the scientific name which
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Look up grapefruit in Wiktionary, the free dictionary.
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Citrus paradisi at Wikispecies
Grapefruit from "Fruits of warm climates" by Julia F. Morton.
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Citrus Variety Collection
Plant List: tro-50119435