The onion (Allium cepa) is one of the oldest and most important of all vegetables. The genus Allium, with about 1250 species, is one of the largest plant genera in the world. Its exact origins are unknown, but it is thought to have originated in either Afghanistan or Iran. Depending on the variety, an onion can be sharp, spicy, tangy and pungent or mild and sweet.
In Canaanite Bronze Age settlements, traces of onions were found alongside fig and dates dating back to 5000 BC. The slaves who built the pyramids were partially reimbursed for their labor with onions, garlic and radishes. The Ancient Egyptians worshipped onions believing their spherical shape and concentric rings symbolized eternal life. They believed the strong scent of onions would bring breath back to the dead and traces of onions were found in the eye sockets of Ramses IV.
In ancient Greece, athletes ate large quantities of onion because it was believed that it would lighten the balance of blood. Roman gladiators were rubbed down with onion to firm up their muscles. During the Middle Ages onions were so valuable that people would pay their rent and give them as gifts.
The advent of convenience foods late in this century greatly increased the demand for onions, especially dehydrated onions. During World War II, the armed forces required huge quantities of granulated, chopped and sliced onions for use in prepared meals and the cultivation and processing of onions exploded. After the war, civilians generally accepted onions and the demand did not abate. Today, onions are found in a bewildering array of recipes they are probably the most widely used spice for flavoring food.
Due to the ease with which, onions are propagated, transported and stored, they are readily available in fresh, frozen, canned, pickled, powdered, and dehydrated forms. Onions are rarely eaten on their own, but are usually a food ingredient. In most foods, onions are chopped, sliced or powdered.