Onions - Did you know?
History
Onions, garlic, leeks and shallots are all members of the same botanical genus
Allium. The origin of onions (Allium cepa) is a mystery. They are not find in the
wild but have been cultivated for at least 5000 years with many writers commenting
on their health benefits.
Health benefits
The flavour of onions is mainly produced when tissue is damaged. Over 60 sulpur
containing flavour compounds are produced. It is these compounds that are thought
to endow onion with many of its health benefits.
Onions has been shown to have anti-asthmatic and anti-histamine activity. This
has been attributed to the cepaenes and thiosulphinates.
Onions are a good source of vitamin C, an antioxidant and essential for efficient
uptake of iron. Red onions are a rich source of antioxidants such as quercetin.
Quercetin also found in green tea has been found to help prevent heart disease and
colon cancer. A special attribute of the onion is that it is one of the few products
where the quercetin is retained during the cooking process.
Raw onion naturally reduces the tendency of the blood to clot so reducing the
chance of a blokage at an atherosclerotic swelling.
Why do onions make you cry?
Onions contain a watersoluble organic sulpur compound called alliin which causes the
tears. This is present in varying amounts in different onions. When the onion bulb is
cut the enzyme alliinase acts on the alliin to produce an organic sulphur compound which
reacts with water (the moisture in your eyes) to produce sulphuric acid which in turn
produces tears and makes your eyes sting.
|
