Onion...is proving its strength outside the culinary world!

What is it?
Onion is a vegetable and the most widely cultivated species of the genus Allium.

Nutrients and phytochemicals

Most onion cultivars are about 89% water, 4% sugar, 1% protein, 2% fibre, and 0.1% fat.

Onions contain phytochemical compounds such as phenolics that are under basic research to determine their possible properties in humans.

What causes their odour?

Thiosulfinate: Allicin

Thiosulfinates are the primary flavour and odour producing molecules in an onion.

Allyl methyl sulfide

If the onion is ingested, thiosulfinates are eventually broken down into allyl methyl sulfide, shown below, which can be removed from the body by exhalation – giving rise to the characteristic ‘onion breath’.

Why chopping onions will make your eyes water?

syn-propanethial-S-oxide

Interestingly, none of the compounds that cause these effects are present in the intact onion; rather, when the cell walls of the onion are damaged by chopping, an enzyme released produces a range of compounds (such as a volatile gas, syn-propanethial-S-oxide, which stimulates nerves in the eye creating a stinging sensation) as a defence mechanism, which act as irritants.

Onion's health advantages

• The phytochemicals in onions along with their vitamin C help improve immunity.
• Onions contain chromium, which assists in regulating blood sugar.
• For centuries, onions have been used to reduce inflammation and heal infections.
• Raw onion lowers the production of bad cholesterol (LDL), thus keeping your heart healthy.
• A powerful compound called quercetin in onions is known to play a significant role in preventing cancer.
• Got bitten by a honeybee? Apply onion juice on the area for immediate relief from the pain and burning sensation.
• Onions scavenge free radicals, thereby reducing your risk of developing gastric ulcers.
• Those bright green tops of green onions are rich in Vitamin A, so do use them often.

What' s new with it?

Artificial muscles created from gold-plated onion cells

Summary

The onion, a humble root vegetable, is proving its strength outside the culinary world -- in an artificial muscle created from onion cells. Unlike previous artificial muscles, this one created by a group of researchers from National Taiwan University, can either expand or contract to bend in different directions depending on the driving voltage applied.

Procedure

The researchers treated the cells with acid to remove the hemicellulose, a protein that makes the cell walls rigid. Then, they coated both sides of the onion layer with gold. When current flowed through the gold electrodes, the onion cells bent and stretched much like a muscle.

NTU researchers show how gold-plated onions can serve as artificial muscles

Reference: compoundchem.com ~ en.wikipedia.org ~ care2.com ~ sciencedaily.com