does chopping an onion make you cry? Unstable
chemicals. Onions produce the chemical irritant known as syn-propanethial-S-oxide. It stimulates the eyes\’ lachrymal glands so they release tears. Scientists used to blame the enzyme allinase
for the instability of substances in
a cut onion. Recent studies from
proved that lachrymatory-factor synthase, (a previously undiscovered
enzyme) is the culprit (Imani et al, 2002). Lachrymatory-factor synthase is released into the air when we
cut an onion. The synthase enzyme converts the amino acids sulfoxides of
the onion into sulfenic acid.
The unstable sulfenic acid rearranges itself into syn-ropanethial-S-oxide. Syn-propanethial-S-oxide gets into the air and comes in contact
with our eyes. The lachrymal glands become irritated and produces
the tears! For
more print resources. onion,
lachrymal gland and crying or tears
in the. How many times you have cried in your whole life????. Once. Twice. Thrice. and how many times you have cried during chopping an onion????. all the time. is this your answer????.
Probably Yes. We mostly deluge our tears during the assassination of this eatable beast. But Have you ever wondered why do onions bring tears to our eyes when we cut them? Get ready to know why. Onions contain amino acid sulfoxides that form sulfenic acids in the onion cells. Both the enzymes and the sulfenic acids are kept separately in the cells. When you cut the onion, the otherwise separate enzymes start mixing and produce propanethiol S-oxide, which is a volatile sulphur compound that starts wafting towards your eyes.
The gas that is emitted reacts with the water of your eyes and forms sulphuric acid. The sulphuric acid thus produced causes burning sensation in your eyes and this in turn leads to the tear glands secreting tears. Thus you end up with watery eyes every time you cut onions at home. It is the sulphur compound in the onions that also leave a typical odour of onions on your hands and utensils even after washing. Cooking the onion inactivates the enzyme, so while the smell of cooked onions may be strong, it doesn\’t burn your eyes.