To some – cooking is an
art; to many it is dull drudgery. In a
TV Channel – the Cuisine expert : ‘ Cut onions
under water’. The other person :
but,…… then, …
how do I breathe ?
Onions are daily used in
sambar & sabjis - Onions and their
relatives are known botanically as
alliums, a plant genus that has been classified at different times as
belonging to the lily family, the amaryllis family, or to a family all its own
called Alliaceae. The ripening process starts when the onion bulb proper
forms. In botany, a bulb is a short stem
with fleshy leaves or leaf bases that function as food storage organs during
dormancy. Actually, it is not this bulb
onion, which is used to make tasteful sambar…. .. it is the smaller ones – ‘the
shallot’ (Allium cepa var. aggregatum).
Onions
generally make people cry :
As onions are sliced, cells are broken open. Onion cells have two
sections, one with enzymes called alliinases, the other with sulfides (amino
acid sulfoxides). The enzymes break down the sulfides and generate sulfenic
acids. Sulfenic acid is unstable and decomposes into a volatile gas which
dissipates through the air and eventually reaches one's eye, where it
will react with the water to form a mild solution of sulfuric acid. The sulfuric
acid irritates the nerve endings in the eyes, making them sting. The tear
glands then produce tears in response to this irritation, to dilute and flush
out the irritant.
Here is
something interesting read on MailOnline of Japanese Scientists researching on
how to cut onions without tears.
For those who do not relish
cooking and cooking onions at that due to the
sobbing that one has to endure while chopping onions in the kitchen, could soon be a thing of the past. Scientists say they have managed produce a
tear-free version of the vegetable thanks to cutting-edge technology. Japanese
scientists disabled the production of the powerful substance that an onion
releases as the knife slices into it, cutting down on the pungent fumes that
bring tears to the eyes.
In a press release,
scientists said that the typical burning sensation of a raw onion was reduced
too. The enzyme responsible is known as lachrymatory factor (LF) synthase. When an onion bulb is cut it causes a chemical
reaction that generates propanthial S-oxide. This makes up the LF enzyme and is
responsible for causing tears. This
reaction also creates thiosulphinate, which creates the onion’s distinctive
flavour.
During tests, scientists
found that LF is formed in the presence of an enzyme called alliinase (AL),
typically found in garlic, as well as Prencso. If any one of these three
components in the reaction was omitted, levels of LF dropped. House Foods
Group, who developed the technology, bombarded a bulb with irradiating ions in
a process that removed these components and drastically reduced the level of
this LF enzyme. The company's researchers led by Shinsuke Imai won the “Ig
Nobel Prize” - an award handed out to honor achievements organisers consider
unintentionally funny - in 2013 for their discovery of the biochemical process
behind how onions make people cry. Their research paper was published in the
journal Nature in 2002.
However, a spokesman said
no decision had yet been made on whether they would commercialise their tear-free
onions. Earlier this year, UK
supermarket Asda began selling its Sweet Red onion which has 'lower pungency
levels'. This results in a milder
flavour and fewer tears. This particular
onion was grown by farmer Alastair Findlay of Bedfordshire Growers and costs
£1.
Interesting !
With regards – S.
Sampathkumar
6th Apr 2015.