Grapefruit - Tropical and Subtropical Fruits: Postharvest Physiology, Processing and Packaging - page 352

reddish tinge (Sauls, 1998). 'Star Ruby' is a lower branch
mutation bearing red-blushed fruits and has a yellow peel
distinctly red-blushed and intensely red pulp and juice, and
is 3 times more colorful than 'Ruby Red' (Morton, 1987).
Though the color decreases with maturity, it is maintained
throughout the season. Some of the juice color is dissipated
by heat in the pasteurization process but there is still enough
for the product to be blended with white or pink grapefruit
juice to provide more consumer appeal (Morton, 1987).
'Sweetie,' a grapefruit × pummelo hybrid released in
1984 in Israel, has all the features of a typical grapefruit
but the flavor is sweet (Morton, 1987).
'Thompson' ('Pink Marsh') cultivar grown in Florida is
a pink-fleshed, seedless fruit. The fruit is oblate to round,
of medium size, 2.75 to 3.75 in. (7-9.5 cm) wide; peel is
light yellow, smooth, with small, inconspicuous oil glands
and faintly aromatic. Pulp is light to deep buff and more or
less flushed with pink, sometimes throughout, occasionally
just near the center. The color of the pulp is most intense
in January and February but fades to nearly amber in late
March/April (Morton, 1987).
The 'Triumph' fruit is oblate to ellipsoid, slightly flat-
tened at both ends, of medium size, with a peel light yellow
and very smooth, with oil glands of medium size. It is
medium thick with a pale pulp and is tender, juicy, and only
faintly bitter, the flavor having a touch of orange; the center
is semihollow and of superior quality, with 35-50 seeds.
Grown only in dooryards in Florida, it has been widely dis-
tributed in citrus regions and does better than 'Marsh' in
South Africa (Morton, 1987).
'Melogold,' a sibling of 'Oroblanco,' is somewhat larger
with a thinner peel that is still considerably thicker than
that of grapefruit. It is a grapefruit-like, triploid hybrid
developed by crossing a sweet pummelo with a seedy,
white, tetraploid grapefruit in 1958. Its fruit is sweet, with
a pummelo-like flavor and few seeds. The rind is yellow-
ish green at maturity. The fruit is larger than the 'Marsh'
variety, and its pummelo-like flavor is considered superior,
though it may have a trace of bitterness at the beginning and
end of the season which extends from early November or
December through February (Morton, 1987). 'Oroblanco'
and 'Melogold' are not common in Texas, but they are
grown in California (Sauls, 1998).

jor white-fleshed grapefruit cultivars are 'Duncan' (seedy)
and 'Marsh' (seedless). A mutation of 'Marsh' with pink
flesh grapfruit is also seedless and is called 'Thompson'
(or 'Pink Marsh'). 'Star Ruby,' 'Ruby Red,' 'Rio Red,' and
'Flame' are other deep red cultivars grown largely in Texas
(Rieger, 2006). A seedy, orange-fleshed fruit that matures
slightly earlier than grapefruit because of its lower acidity,
it is grown in a few home plantings in Texas. It is known
by various names, including “New Zealand Grapefruit”
and “Poorman Orange”. The fruit and tree are very sim-
ilar to grapefruit but it is probably a pummelo hybrid that
may have originated in China or Australia (Sauls, 1998).
'Chironja' is grapefruit-orange hybrid that was discovered
in Puerto Rico. The fruit is large and oblate like grapefruit,
with peel and flesh color more like that of orange. Its flavor
is pleasant, lacking the bitterness characteristic of grape-
fruit. It is grown to a limited extent in Puerto Rico but not
elsewhere.
'Oroblanco,' a hybrid between grapefruit and an acid-
less pummelo, was released in the United States in 1981
(Morton, 1987; Sauls, 1998). The fruit form and size are
similar to 'Marsh,' with a peel paler and thicker and a
pulp paler, with a larger, hollow center. It is tender, juicy,
and nonbitter and has a faintly astringent aftertaste before
full maturity or in cooler climates. It seems better adapted
to California's inland citrus locations than to desert sites
(Morton, 1987). It is sweet, without the bitterness of grape-
fruit, with few seeds, and is a little larger than a grape-
fruit. The rind is smooth, very thick, and greenish yellow
at full maturity, which is usually December to January in
California (Sauls, 1998).

Marketing terminology of varieties
Grapefruits are categorized as white (blond), pink, or ruby
(red). However, this terminology does not reflect their skin
color, which is either yellow or pinkish-yellow, but rather
describes the color of their flesh (Fig. 19.3). Some varieties
contain seeds, while others are seedless (Wood, 1988).

CONSUMPTION TREND, SIGNIFICANCE TO
HUMAN HEALTH
The top ten countries by grapefruit consumption are shown
in Fig. 19.4. The Carribean nations (Dominican Republic,
Belize, Grenada, and Saint Lucia) lead in per capita grape-
fruit consumption.
Citrus fruits, and, in particular, grapefruit, and their
products are widely consumed in developed countries, al-
though consumption per capita is increasing in developing

Grapefruit hybrids
Hybrids are obtained from crosses of tangerine with or-
ange (tangors or grapefruit (tangelos)). Tangelo is a com-
mon hybrid between mandarin and grapefruit (Tangelo =

mandarin × grapefruit) (Seymour et al., 1993). The ma-