Onion

Description
The onion is believed to have originated in Asia, though it is likely that onions may have been growing wild on every continent. Dating back to 3500 BC, onions were one of the few foods that did not spoil during the winter months. Our ancestors must have recognized the vegetable's durability and began growing onions for food.

The onion became more than just food after arriving in Egypt. The ancient Egyptians worshipped the onion, believing that its spherical shape and concentric rings symbolized eternity. Of all the vegetables that had their images created from precious metals by Egyptian artists, only the onion was made out of gold.

Today, onions are used in a variety of dishes and rank sixth among the world's leading vegetable crops. Onions not only provide flavor; they also provide health-promoting phytochemicals as well as nutrients.

About onions
A vegetable, which belongs to the lily family of plants, that is grown for its edible bulb, which most often serves to flavor a variety of foods. onions are categorized as being either green or dry onions. Green onions, known as scallions, are harvested before they mature, while their stems are still green. The bulb is generally white-skinned with a flavor that ranges from mild to peppery and pungent. Common varieties that are eaten raw or are used to flavor soups and salads include white Lisbon and Ishikura. Dry onions, also known as mature onions, are harvested when their shoot has died and layers of papery thin skin cover a firm juicy flesh. There are a wide variety of shapes and sizes, ranging from small round pearl onions to the larger spherical-shaped Spanish onions. The dry onions can be classified as either sweet or storage onions and are most often sold as a red, yellow or white onion. Sweet onions, which contain a higher water content but a lower sulfur content, spoil quickly and are less pungent than other varieties. They are most often eaten raw or only lightly cooked. Common varieties of sweet onions include: Arizona onion, Carzalia sweet, Florida Sweet, Granex, Maui, sweet Imperial, Oso sweet, Texas spring sweets, Spring onions, Vidalias, Walla Wallas, and Texas 1015's. Storage onions contain a higher sulfur content and less moisture, so they can be kept in storage for longer periods of time, developing a more pungent flavor as they age. The storage onion is best when cooked, providing a sharper and more flavorful taste than sweet onions. Some of the more common varieties of dry onions will include the Bermuda red, cipolline or Borettana white, creole red, fall onion, Spanish yellow, Italian red, pearl white, red torpedo, white onion and yellow onion.

When selecting onions, choose those that have unblemished bulbs with thin skins and crisp leaves. Avoid any that are sprouting. onions, which are available throughout the year, should be stored in a cool dry location and may be stored uncut for a month or longer.

When preparing onions, slice or chop by starting at the end opposite the root. onions contain gases that cause our eyes to tear, and since more gases reside in the root end, chop or slice it last. It is generally considered best to slice onions with the grain, often refered to pole to pole or in the direction of end to end. To cut an onion with the grain, start by slicing off both ends, creating a round flat spot on each end. Set the onion down resting on the flat spot of either end, and vertically cut the onion in half from top to bottom, resulting in two pieces split in half. Now place one half down on the flat side of the most recent cut, which is the center of the onion. The onion can then be cut straight down vertically, end to end making even spaced cuts that are made with the grain. Cutting onions in this manner provides a more pleasing presentation for with foods containing braised, cooked or fresh onions.

Other ways to decrease tears when peeling or cutting onions are by chilling onions prior to slicing or running cold water over the onion while slicing. To remove the pungent odor remaining on any flesh coming in contact with an onion, use stainless steel products produced specifically for removing onion aroma or any stainless steel item that can be rubbed through or across the exposed flesh as it is washed.

Selection
Most onions are sold loose by the pound, although some types are sold in bags or small boxes. Look for onions that feel dry and solid all over, with no soft spots or sprouts. The neck should be tightly closed and the outer skin should have a crackly feel and a shiny appearance. Onions should smell mild, even if their flavor is not. Avoid selecting onions with green areas or dark patches.

Storage
Onions should be kept in a cool, dry open space away from bright light. Onions do best in an area that allows for air circulation. Because onions absorb moisture, do not store onions below the sink. Also, do not place onions near potatoes because potatoes give off moisture and produce a gas that causes onions to spoil more quickly. Spring/summer onions usually store for about two weeks and storage onions for about three to four weeks.

Varieties
Onions came in a variety of sizes, colors and shapes. They are often broken down into three categories: spring/summer, storage, and pearl onions. Spring/summer onions are grown primarily from fall to spring in warm weather areas and have a soft flesh and a mild or sweet taste. These varieties are generally shipped right after harvesting. Storage onions have a firm flesh, dry, crackly outer skins and have a pungent flavor. After a brief period of drying, these onions are stored for several months before shipping. Pearl onions are often called white onions and are densely planted to make the onions smaller. There are no nutritional differences among these onion types.

Onions also come in three colors — yellow, red, and white. Approximately 88 percent of the onion crop is devoted to yellow onion production, with about 7 percent red onions and 5 percent white onions.

Yellow onions are full-flavored and are a reliable standby for cooking almost anything. Yellow onions turn a rich, dark brown when cooked and give French Onion Soup its tangy sweet flavor. The red onion, with its wonderful color, is a good choice for fresh uses or in grilling and char-broiling. White onions are the traditional onion used in classic Mexican cuisine. They have a golden color and sweet flavor when sautèed.

Source

 * Fruit & Vegetable of the Month: Onions by the US Centers for Disease Control & Prevention, public domain government resource—original source of article