Onions belong to the Allium family of plants, which also includes chives, garlic, and leeks. These vegetables have characteristic pungent flavors and some medicinal properties. Onions vary in size, shape, color, and flavor. The most common types are red, yellow, and white onions. The taste of these vegetables can range from sweet and juicy to sharp, spicy, and pungent, often depending on the season in which people grow and consume them. The onion is likely native to southwestern Asia but is now grown throughout the world, chiefly in the temperate zones. Onions are low in nutrients but are valued for their flavour and are used widely in cooking. They add flavour to such dishes as stews, roasts, soups, and salads and are also served as a cooked vegetable.
Most whole onions are slightly dried before marketing, making their skins dry and paper-thin. Onions are also available in various processed forms. Boiled and pickled onions are packed in cans or jars. Frozen onions are available chopped or whole, and bottled onion juice is sold for use as a flavouring. Dehydrated onion products have been available since the 1930s; such products include granulated, ground, minced, chopped, and sliced forms. Onion powder is made by grinding dehydrated onions and is sometimes packaged in combination with salt. Dried onion products are used in a variety of prepared foods and are also sold directly to the consumer for use as condiments.
