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Wednesday, June 1, 2022

To cut onions without crying ~ cut them underwater !!!

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 honour 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.

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