Valencia oranges, sometimes called common oranges, are one of the most important types of citrus trees worldwide. Valencia orange types are commonly used for juicing and processing rather than eating fresh. They are smaller and more juicy than navel oranges, with few seeds and a thinner skin. Trees are generally more vigorous than navel orange trees. Fruit will store well on the tree, giving it the ability to sweeten up better than navels if there is less heat. The fruit has a higher acid to sugar ratio than navel oranges, and produces superior juice. Valencia oranges generally ripen in the summer, helping to create a fresh supply of oranges year round. They are likely to display alternate bearing, having heavy loads of fruit one year and a lighter crop the next.
Valencia oranges also play a big part in California history, and became the center of large citrus growing regions such as Orange County. Valencia oranges are ideally suited to growing in only a few mild-winter areas of the United States. First imported from Azores, Portugal to California in the 1800's, they quickly became popular. In the early 1900's, the orange industry may have provided up to a third of the employment in orange growing regions of California. However, in the mid 1900's, it soon became more profitable to grow houses than oranges. While some Valencia oranges are still grown in California's Central Valley, much of production was shifted to Florida, Texas, and Arizona. Today, Valencia oranges account for nearly half of Florida's citrus production. They can be grown in other areas, but usually with special care, including indoor protection during cold winters.
Oranges are small trees in the Citrus genus and the family Rutaceae, the rue family, with many of its numerous plant members known for producing strongly aromatic, flavorful, or medicinal leaves and/or fruit. There are several types of Valencia varieties, including Midknight, Campbell, and Delta types. Sweet oranges, and sweet citrus in general, require heat to develop high sugar content in fruits. Valencia oranges have the capacity to hang on the tree, giving them the opportunity to develop even more concentrated sugars.
The agricultural origins and exact native range of oranges remains unknown; it is believed that oranges were first cultivated around 2500 BC in China, and originated in Southern China, Northeast India, and/or parts of Southeast Asia. While various citrus were known in Italy as early as the 11th Century, sweet oranges were unknown in the West until the late 15th Century, after which they spread rapidly, and were known throughout Europe by the mid-17th Century.
Oranges are known for their high vitamin C content, but also contain dietary fiber, thiamin, and potassium. One medium-sized orange can contain up to 100% or more of the USDA recommended daily vitamin C.