on oranges:

It is only in comparatively recent centuries that oranges, in Western countries, have actually been eaten as a food. Their earliest popularity in Europe seems to have been based on the ornamental appearance of the trees and the inspiring aroma of the peel and the blossoms.

At the table, they were used as a seasoning for meat and fish and seldom consumed in any other way. Before 1500, European orange growers mainly grew Bitter Oranges, because they were more aromatic, better as seasoning, and hence more valuable.

Dinner guests could measure their importance in the regard of their hosts by the number of oranges that came to the table. One fourteenth-century cookbook, describing a dinner given by an abbott of Langy for his superior, the Bishop of Paris, indicates how impressive a meal it was by noting that the roast fish was seasoned with powdered sugar and Sour Oranges.

In 1529, the Archbishop of Milan gave a sixteen-course dinner that included caviar and oranges fried with sugar and cinnamon, brill and sardines with slices of orange and lemon, one thousand oysters with pepper and oranges, lobster salad with citrons, sturgeon in aspic covered with orange juice, fried sparrows with oranges, individual salads containing citrons into which the coat of arms of the diner had been carved, orange fritters, a soufflé full of raisins and pine nuts and covered with sugar and orange juice, five hundred fried oysters with lemon slices, and candied peels of citrons and oranges.

At about that time, Portuguese ships returned home from India with sweet orange trees, and a new type spread through Europe. It became known as the Portugal Orange, and it quickly replaced the Bitter Orange in popularity throughout the continent. The word “Portugal” became synonymous with good sweet oranges in numerous countries, and, in fact, sweet oranges are still called Portugals in Greece, Albania, Rumania, parts of the Middle East, and some parts of Italy.

In most of Western Europe, the favor held by the Portugal Orange was less enduring. Within a century after the first trees had come from India, Portuguese missionary monks sent word back from China that Chinese oranges were sweeter than sugar itself. One Portuguese Jesuit wrote that “the oranges of Canton might well be muscat grapes disguised.”

In 1635, a Chinese orange tree reached Lisbon, and before long the China Orange— a term still used in many countries to denote a fine sweet orange— was in demand all over Europe. The botanical name of the modern sweet orange, in fact, is Citrus sinensis.

McPhee, John (2011-04-01). Oranges (p. 70). Farrar, Straus and Giroux. Kindle Edition.