It is known that the sweet orange (Citrus sinensis) was introduced to Europe only in the 15th century. Some people think that citrus was brought to Europe in 1429 after the journey of Vasco da Gama to India. Up to 15-18 centuries oranges were grown only in greenhouses. The biggest greenhouses were in London, Paris and in the vicinity of St. Petersburg. However, in southern Europe in the 18th century there were some attempts made to cultivate citrus and in the open field.
The Spanish and Portuguese colonizers brought orange, lemon along with other species to West Africa Central and South America in the 15-16 century. Somewhat earlier, Arab and Indian sailors introduced these species to the east coast of Africa. So orange gradually became one of the major cultivars of tropical and subtropical regions of the globe.
According to the scientists orange, like most plants of the genus Citrus originates from Southeast Asia. Thus, one of the Chinese manuscripts dating back to 1178 describes 27 best varieties of oranges and tangerines. Currently, wild forms the orange have not been found.
The orange is the fruit of citrus tree in the family Rutaceae (Rutaceae). The leaves are solid, evergreen. The flowers are white, grow in blossom clusters. The fruit generally has ten segments inside, and contains up to six seeds (or pips). It has thick and soft skin. The fruit skin contains an essential oil. The shape, size, properties of juice and taste differ depending of the variety of the fruit. Apart from the sweet oranges, bitterish bigarades and sour lemons there are some other varieties with interesting and useful properties. Total valued more thin-skinned, juicy oranges and a full-fledged Thin-skinned, juicy and weighty oranges such as Maltese, Genoese are valued above all.
Chemical composition of oranges:
Fruits contain citric acid (0.6-2.0%), sugar (from 8.6 to 15%); vitamin C, carotene, P (hesperidin, eriodiktiol), pectin and nitrogenous compounds, cellulose, carbohydrates, volatile, minerals (potassium, calcium, phosphorus) and in the fruit skin there are some essential oils. Orange fruits contain 87.7% of solids, including 8.4% carbohydrate, 0.9% proteins, 1.4% fat and 0.4-0.5% pektines. The orange colour of the fruit skin is determined by availability of cryptoxanthin . The orange peel contains 1,2 - 2% of essential oils of several types.
100 grams of oranges - 38 kcal.
197 mg potassium / 100 g,
34 mg calcium / 100 g,
magnesium 13 mg / 100 g,
Phosphorus 23 mg / 100 g,
iron 0.3 mg / 100 g,
sodium 13 mg / 100 g
vitamin C - 60 mg / 100 g,
vitamin B1 - 0.03 - 0.04 mg / 100 g,
Carotene 0.05 - 0.25 mg / 100 g,
Vitamin B2 0.04 mg / 100 g,
vitamin PP - 0.2 mg / 100 g