autumn and winter The pigments tend to accumulate at the blossom end and in vesicles immediately next to the segment walls, and continue to accumulate after harvest when the fruits are held in cold storage The pigments and their phenolic precursors give blood oranges a higher antioxidant value than other oranges The unique flavor of blood oranges combines citrus notes with a distinct raspberry-like aroma Acidless oranges are grown in small numbers in north Africa, Europe, and South America, and have about a tenth the acidity — and less orange aroma — of common and navel oranges Sour oranges come from a different species than the kinds described above, and are both sour and bitter (thanks not to limonin but a related compound, neohesperidin), with an intense and distinctive peel aroma They arrived in Spain and Portugal in the 12th century, and soon displaced quince as the main ingredient in marmalade Sour-orange flowers are used to make orange flower water Grapefruit The grapefruit originated as a hybrid of the sweet orange and pummelo in the Caribbean in the 18th century, and is still mainly grown in the Americas The red types owe their color to lycopene, and first appeared as chance mutations in Florida and in Texas early in the 20th century (the more recent and popular Star Ruby and Rio Red varieties were created by intentionally inducing mutations with radiation) Unlike the anthocyanin coloration of blood oranges, grapefruit lycopene requires consistent high growing temperatures to develop well, appears evenly through all the juice vesicles, and is stable to heat The characteristic moderate bitterness is caused by a phenolic substance called naringin, whose concentration declines as the fruit ripens Like navel oranges, grapefruits also contain a precursor of limonin, and its ... Grapefruit The grapefruit originated as a hybrid of the sweet orange and pummelo in the Caribbean in the 18th century, and is still mainly grown in the Americas The red types owe their color to lycopene, and first appeared... owe their color to lycopene, and first appeared as chance mutations in Florida and in Texas early in the 20th century (the more recent and popular Star Ruby and Rio Red varieties were created by intentionally inducing... mutations with radiation) Unlike the anthocyanin coloration of blood oranges, grapefruit lycopene requires consistent high growing temperatures to develop well, appears evenly through all the juice vesicles, and is stable to