The orange, specifically the sweet orange, is the fruit of the citrus species Citrus Sinensis in the family Rutaceae. However, the fruit of the Citrus Aurantium is considered a bitter orange. It is a hybrid between pomelo and mandarin, it has genes that are 25% pomelo and 75% mandarin, however it is not a simple hybrid but done over multiple generations. The chloroplast genes, ergo the maternal line, seem to be pomelo. It is unknown in the wild state, and is assumed to have originated in sourthern China, northeastern India and perhaps southeastern Asia. In Europe, citrus fruits, introduced to Italy by the crusaders in the 11th century, were grown widely in the south for medicinal purposes, but the sweet orange was unknown until the late 15th century, or perhaps the beginnings of the 16th century, when Italian and Portuguese merchants brought orange trees into the Mediterranean area. Shortly afterward, the sweet orange quickly was adopted as an edible fruit, and was considered a luxury item. Wealthy people grew oranges in private conservatories, called orangeries. By 1646, the sweet orange was well known throughout Europe.
- Orange trees are widely grown in tropical and subtropical climates for their sweet fruit. As of 2012, sweet oranges accounted for approximately 70% of citrus production. In 2010, 68.3 million metric tons of oranges were grown worldwide.
- Oranges, whose flavor may vary from sweet to sour, are commonly peeled and eaten fresh, or squeezed for juice. The thick bitter rind is usually discarded, but can be processed into animal feed by desiccation, using pressure and heat. It is also used in certain recipes as a food flavoring or garnish.
- The outermost layer of the rind can be thinly grated with a zester (or fork
) to produce orange zest. Zest is popular in cooking because it contains oils and has a strong flavor similar to that of orange pulp. The white part of the rind, including the pith, is a source of pectin and has nearly the same amount of vitamin C as the flesh and other nutrients.
- Although not as juicy or tasty as the flesh, orange peel is edible and has significant contents of vitamin C, dietary fiber, total polyphenols, carotenoids, limonene and dietary minerals, such as potassium and magnesium.
- Sweet orange oil is a by-product of the juice industry produced by pressing the peel. It is used for flavoring food and drinks, and also in the perfume industry and aromatherapy for its fragrance. Sweet orange oil consists of approximately 90% D-limonene, a solvent used in various chemicals, such as wood conditioners, detergents and hand cleansers. It is an efficient cleaning agent with a pleasant smell, promoted for being environmentally friendly.