Onion
Allium cepa
Onions have been grown and enjoyed by humans since the very earliest days of food
production and were a popular staple food in ancient Egypt—the people who built
the pyramids were fuelled by the humble onion The ancients regarded its shape as
being a symbol of the universe, and the name “onion” is thought to be derived from
the Latin “unus”, meaning “one”.
Garlic and onions are surrounded with folklore regarding their magical
properties; among other attributes, they are reputed to increase fertility in men and
milk in nursing mothers, and to cure headaches when mixed with milk and vinegar.
Onions are also highly beneficial in nutritional terms, providing a rich source of
Vitamins B 1 , C and E and certain trace elements. Their carbohydrate content ranges
from 5% to about 11%; 100 g of edible portion provides about 36 kcal energy value.
Plants of the Alliaceae (Allium) family contain alkaloids known as Alliins. The
best source is garlic. Alliins are now known to have a positive effect on heart
diseases and also to prevent growth of malignant (carcinogenic) cells, and it can be
argued that the main role of the Onion family is anti-carcinogenic and
cardioprotective rather than nutritional.
Shallots and onions are often regarded as being the same species, Allium cepa.
were annuals. Other members of the Alliaceae family include ornamentals such as
hyacinth, tulip and lily of the valley. Unfortunately for food producers, the Allium
family sometimes behave like annuals, by setting seed—“bolting”—in their first
year (1Ea). This tends to happen either if the variety is not adapted to the area or if
the growing conditions change for the worse, eg drought. The seed heads are, on the
other hand, highly decorative, and provide plentiful nectar for honey bees and other
insects. Other onion types such as the Welsh and Tree Onions (see below) are
perennial.
Unlike most of the other vegetables onions are monocotyledons; they grow from
the base of their leaves, pushing their leaves up and out from this base.
Dicotyledons, by contrast, grow outwards from the edges of the leaves.
Classification,or taxonomy, of the myriad onion varieties is not straightforward
and botanists continue to dispute the issue. The genus Allium was for many years
included in the Liliaceae family, though these days most botanists broadly agree that
onions should be placed in the Alliaceae family, and that there are three groups, or
botanical varieties, of Allium cepa:
234 TONY WINCH
Oignon (French); Zwiebel (German); Cebolla (Spanish); Cebola (Portuguese);
Osapola (Angola); Piyaz (Hindi, Pashtu and Dari); Shinkurt (Amharic), Shinkurtee
(Oromifa)
are both closely related to garlic (A. sativum), chives (A. schoenoprasum) and leeks
Other authorities argue that the shallot is a separate species, A. ascalonicum. The two
(A. porrum). Most species in this family are biennial, but are mainly treated as if they