Orange



The Orange Citrus x sinensis is a Citrus tree, and the fruits of this tree. It is a hybrid of cultivated origin, possibly between C. maxima and C. reticulata. It is a small tree growing to 10 m tall, with thorny shoots and evergreen leaves 4-10 cm long. The fruit originated in southeast Asia, either in India, Vietnam or southern China. The original fruit is rather bitter compared to modern cultivars, as is referred to as the sour orange (or alternately, bitter, bigarade or Seville orange). The sour taste is in fact attributed to the slight acidity of the orange's juice.

Cultivation and uses

Oranges are widely grown in warm climates worldwide. The flavors of orange vary from sweet to sour. The fruit is commonly peeled and eaten fresh, or squeezed for its juice. It has a thick bitter rind that is usually discarded, but can be processed into animal feed by removing water using pressure and heat. It can also be used in certain recipes as flavoring or a garnish. The outer-most layer of the rind is grated or thinly veneered with a tool called a zester, to produce orange zest which is popular in cooking because it has a similar flavor to the inner part of the orange. The white part of the rind, pith, is almost always discarded.

All citrus trees are of a single genus, Citrus, and remain largely interbreedable; that is, there is only one "superspecies" which includes lemons and limes as well as oranges. Nevertheless names have been given to the various members of the citrus family, oranges often being referred to as Citrus sinensis and Citrus aurantium. All members of the genus Citrus are considered berries because they have many seeds, are fleshy, soft and derive from a single ovary.

A number of cultivars of orange are now cultivated widely. The sweet orange (Citrus x aurantium) was first grown in Spain, and has become the most popular variety. The sweet orange will grow to different sizes and colors due to local conditions, most commonly with ten carpels (slices) inside.

A single mutation in an orchard of sweet oranges planted at a monastery in 1820 in Brazil led to the navel orange (aka Washington, Riverside or Bahia navel). A single cutting of the original was then transplanted to Riverside, California in 1870, creating a new market worldwide. The mutation caused a 'twin' fruit, with a smaller orange embedded in the outer fruit opposite the stem. From the outside the smaller, undeveloped, twin leaves a human navel-like formation at the top of the fruit. Navel oranges are almost always seedless, and tend to be larger than the sweet orange. They are produced without pollination (parthenocarpy).

The Valencia or Murcia orange is one of the sweet oranges used for juice extraction. It is a late-season fruit. It is a popular variety of orange when the navel oranges are out of season.

The blood orange has streaks of red in the fruit, and when squeezed the juice is often reddish. The mandarin orange is similar, but smaller and sweeter, and the scarlet navel is a variety with the same diploid mutation as the navel orange.

Bitter oranges are used in marmalade and as an ingredient in the liqueurs triple sec and curaçao.