The blood orange is a variety of orange (Citrus × sinensis) (also referred to as raspberry orange) with crimson, near blood-colored flesh.
The distinctive dark flesh color is due to the presence of anthocyanins, a family of polyphenol pigments common to many flowers and fruit, but uncommon in citrus fruits. Chrysanthemin (cyanidin 3-O-glucoside) is the main compound found in red oranges. The flesh develops its characteristic red color when the fruit develops with low temperatures during the night. Sometimes, dark coloring is seen on the exterior of the rind as well. This depends on the variety of blood orange. The skin can be tougher and harder to peel than that of other oranges. Blood oranges have a unique flavor compared to other oranges, being distinctly raspberry-like in addition to the usual citrus notes. The anthocyanin pigments of blood oranges begin accumulating in the vesicles at the edges of the segments, and at the blossom end of the fruit, and continue accumulating in cold storage after harvest.
The blood orange is a natural mutation of the orange, which is itself a hybrid, probably between the pomelo and the tangerine. Within Europe, the arancia rossa di Sicilia (red orange of Sicily) has Protected Geographical Status. In the Valencian Community, it was introduced in the second half of the 19th century.
