2007-07-20 04:23:19 · 7 answers · asked by Humaira Khan 2 in Science & Mathematics ➔ Biology
As onions are sliced, cells are broken, allowing enzymes called alliinases to break down sulfides and generate sulphenic acids (amino acid sulphoxides). Sulphenic acids are unstable and decompose into a volatile gas. The gas dissipates through the air and eventually reaches the eye, where it reacts with the water to form a dilute solution of sulphuric acid. This acid irritates the nerve endings in the eye, making them sting. Tear glands produce tears to dilute and flush out the irritant.
2007-07-20 04:31:44 · answer #1 · answered by Anonymous · 0⤊ 0⤋
Onions and eye irritation
As onions are sliced, cells are broken, allowing enzymes called alliinases to break down sulfides and generate sulfenic acids (amino acid sulfoxides). Sulphenic acids are unstable and decompose into a volatile gas called syn-propanethial-S-oxide. The gas dissipates through the air and eventually reaches the eye, where it reacts with the water to form a dilute solution of sulfuric acid. This acid irritates the nerve endings in the eye, making them sting. Tear glands produce tears to dilute and flush out the irritant.[6]
Supplying ample water to the reaction prevents the gas from reaching the eyes. Eye irritation can, therefore, be avoided by cutting onions under running water or submerged in a basin of water. Rinsing the onion and leaving it wet while chopping may also be effective. Another way to avoid irritation is by not cutting off the root of the onion, or by doing it last, as the root of the onion has a higher concentration of enzymes. Chilling or freezing onions prevents the enzymes from activating, limiting the amount of gas generated. Using a sharp blade to chop onions will limit the cell damage and the release of enzymes that drive the irritation response. Having a fire, such as a candle or a burner, will help as the heat and flames will draw in the onion gas, burn it, and then send it up with the rest of the flame exhaust. In the heat, the chemical changes such that it no longer irritates the eyes.
The volume of sulphenic acids released, and the irritation effect, differs among Allium species.
A firm in Toronto, Canada, attempted to utilize this property of onions in the manufacture of a form of tear gas for civilian use. It was marketed in 1991 but was unsuccessful as it had an effective shelf life of only three months.[citation needed]
The characteristic odour of onions can be removed with lemon.[citation needed]
Got that at wikipedia. For more go to the web site below.
2007-07-20 04:32:34 · answer #2 · answered by ghouly05 7 · 0⤊ 1⤋
As onions are sliced, cells are broken, allowing enzymes called alliinases to break down sulfides and generate sulfenic acids (amino acid sulfoxides). Sulphenic acids are unstable and decompose into a volatile gas called syn-propanethial-S-oxide. The gas diffuses through the air and eventually reaches the eye, where it reacts with the water to form a dilute solution of sulfuric acid. This acid irritates the nerve endings in the eye, making them sting. Tear glands produce tears to dilute and flush out the irritant
2007-07-21 01:24:20 · answer #3 · answered by kritika 2 · 0⤊ 0⤋
Which Acid In Onion
2017-02-24 06:51:56 · answer #4 · answered by ? 4 · 0⤊ 0⤋
Well, the World Book doesn't state which acid it is but it mentions : The typical onion smell is due to the substance allyl sulphide.
2007-07-20 05:41:16 · answer #5 · answered by Stella 2 · 0⤊ 0⤋
I think onions contain sulphuric acid. Not sure though.
2007-07-20 04:27:13 · answer #6 · answered by dachawawa 3 · 0⤊ 0⤋
how to prepare myself for suicide?
2013-10-25 21:56:09 · answer #7 · answered by Sathasivam 1 · 0⤊ 0⤋