Onions and Tears

There are many methods recommended for cutting onions to avoid tears. Each method has its supporters. Try each of them, if one works for you, use it.

Methods:

• cut the root off last; • refrigerate before cutting; • peel them under cold water; • have a fan behind you or alongside to blow the vapors away; • place a piece of bread on the knife tip to absorb the fumes; • chew gum while peeling and slicing onions. • hold you breath and cut them as quick as you can • have someone else cut them for you!

Why we cry when cutting onions.
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 Japan, however, proved that lachrymatory-factor synthase, (a previously undiscovered enzyme) is the culprit (Imani et al, 2002).
The process goes as follows:

• Lachrymatory-factor synthase is released into the air when we cut an onion. • The synthase enzyme converts the sulfoxides (amino acids) 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!