The distinctive dark flesh color is due to the presence of anthocyanins, a family of polyphenol pigments common to many flowers citrus sinensis moro fruit, but uncommon in citrus fruits. The blood orange is a natural mutation of the orange, which is itself a hybrid, probably between the pomelo and the tangerine.
Moro’, the newest variety of the three. While also pigmented, Cara cara navels and Vainiglia sanguignos have pigmentation based on lycopene, not anthocyanins as blood oranges do. The ‘Moro’ is the most colorful of the blood oranges, with a deep red flesh and a rind with a bright red blush. The flavor is stronger and the aroma is more intense than a normal orange.
This fruit has a distinct, sweet flavor with a hint of raspberry. The name ‘Tarocco’ is thought to be derived from an exclamation of wonder expressed by the farmer who was shown this fruit by its discoverer. It is a medium-sized fruit and is perhaps the sweetest and most flavorful of the three types. The most popular table orange in Italy, it is thought to have derived from a mutation of the ‘Sanguinello’.
It is referred to as “half-blood”, because the flesh is not accentuated in red pigmentation as much as with the ‘Moro’ and ‘Sanguinello’ varieties. The University of California, Riverside Citrus Variety Collection has delineated three subcultivars of ‘Tarocco’. The ‘Bream Tarocco’, which was originally donated by Robert Bream of Lindsay, California, is of medium to large fruit with few to no seeds. Spain in 1929, has a reddish skin, few seeds, and a sweet and tender flesh. Sanguinello’, the Sicilian late “full-blood” orange, is close in characteristics to the ‘Moro’.
Where grown in the Northern Hemisphere, it matures in February, but can remain on trees unharvested until April. Fruit can last until the end of May. The peel is compact, and clear yellow with a red tinge. Blood oranges may have originated in the southern Mediterranean, where they have been grown since the 18th century. They are a common orange grown in Italy.