Editing Wasabi (section)

==Chemistry==
[[File:Wasabi, Iwasaki Kanen 1828.jpg|thumb|left|Drawing of a wasabi plant, by [[Iwasaki Kanen]], 1828]]

The chemical in wasabi that provides its initial pungency is the volatile compound [[allyl isothiocyanate]], which is produced by [[hydrolysis]] of allyl glucosinolate, a natural thioglucoside (conjugates of the sugar glucose and sulfur-containing organic compounds); the hydrolysis reaction is catalyzed by [[myrosinase]] and occurs when the enzyme is released on cell rupture caused by maceration&nbsp;– e.g., grating&nbsp;– of the plant.<ref name="Ina">{{cite journal |author1=Kazuo Ina |author2=Hiroji Ina |author3=Mikako Ueda |author4=Akihito Yagi |author5=Isao Kishima |year=1989 |title=ω-Methylthioalkyl Isothiocyanates in Wasabi |journal=[[Agricultural and Biological Chemistry]] |volume=53 |issue=2 |pages=537–538 |doi=10.1271/bbb1961.53.537 |doi-access=free }}</ref><ref name="Masuda">{{cite book |author1=Hideki Masuda |author2=Yasuhiro Harada |author3=Kunio Tanaka |author4=Masahiro Nakajima |author5=Hideki Tabeta |year=1996 |chapter=Characteristic Odorants of Wasabi (''Wasabia japonica matum''), Japanese Horseradish, in Comparison with Those of Horseradish (''Armoracia rusticana'') |title=Biotechnology for Improved Foods and Flavors |pages=67–78 |doi=10.1021/bk-1996-0637.ch006 |series=ACS Symposium Series |volume=637 |isbn=9780841234215 |publisher=[[American Chemical Society]] }}</ref><ref>{{cite web |url=http://www.freshwasabi.com/tech.aspx |title=Condiments – Wasabi: real vs. fake |url-status=dead |archive-url=https://web.archive.org/web/20110711040526/http://www.freshwasabi.com/tech.aspx |archive-date=11 July 2011 |access-date=9 August 2016}}</ref> The same compound is responsible for the pungency of horseradish and mustard. Allyl isothiocyanate can also be released when the wasabi plants have been damaged because it is being used as a defense mechanism.<ref>{{Cite journal|last1=Atsumi|first1=A |last2=Saito|first2=T |year=2015|title=Volatiles from wasabi inhibit entomopathogenic fungi: implications for tritrophic interactions and biological control|journal=Journal of Plant Interactions|volume=10|issue=1|pages=152–157 |issn=1742-9145|doi=10.1080/17429145.2015.1039613|doi-access=free|bibcode=2015JPlaI..10..152A |hdl=10297/9349|hdl-access=free}}</ref> The sensory neural target of mustard oil is the chemosensory receptor, [[TRPA1]], also known as the wasabi receptor.<ref>{{Cite journal|last1=Zhao|first1=Jianhua|last2=Lin King|first2=John V.|last3=Paulsen|first3=Candice E.|last4=Cheng|first4=Yifan|last5=Julius|first5=David|date=2020-07-08|title=Irritant-evoked activation and calcium modulation of the TRPA1 receptor|journal=Nature|volume=585|issue=7823|language=en|pages=141–145|doi=10.1038/s41586-020-2480-9|pmid=32641835|pmc=7483980|bibcode=2020Natur.585..141Z|s2cid=220407248|issn=1476-4687}}</ref>

The unique flavour of wasabi is a result of complex chemical mixtures from the broken cells of the plant, including those resulting from the hydrolysis of thioglucosides, including [[sinigrin]]<ref>{{cite journal |last1=Yu |first1=E. Y. |last2=Pickering |first2=I. J. |last3=George |first3=G. N. |last4=Prince |first4=R. C. |title=In situ observation of the generation of isothiocyanates from sinigrin in horseradish and wasabi |journal=Biochimica et Biophysica Acta (BBA) - General Subjects |volume=1527 |issue=3 |pages=156–160 |doi=10.1016/s0304-4165(01)00161-1 |pmid=11479032 |date=15 August 2001}}</ref> and other glucosinolates, into glucose and methylthioalkyl [[isothiocyanate]]s:<ref name="wasabicen"/><ref name="Ina"/><ref name="Masuda"/>

* 6-(Methylsulfinyl)hexyl isothiocyanate ([[6-MITC]])
* 7-Methylthioheptyl isothiocyanate
* 8-Methylthiooctyl isothiocyanate

Such isothiocyanates [[antimicrobial|inhibit microbial growth]], perhaps with implications for preserving food against spoilage and suppressing oral [[bacterial growth]].<ref>{{cite book |url=https://books.google.com/books?id=TdQtFQZ5XCQC&q=antimicrobial+isothiocyanates&pg=PA12 |title=Food preservation techniques |first1=P. |last1=Zeuthen |first2=Leif |last2=Bøgh-Sørensen |page=12 |publisher=Woodhead Publishing Limited |year=2003 |isbn=978-1-85573-530-9 |access-date=9 August 2016}}</ref>

Because the burning sensations of wasabi are not oil-based, they are short-lived compared to the effects of [[capsaicin]] in [[chilli pepper]]s and are washed away with more food or liquid. The sensation is felt primarily in the nasal passage and can be painful depending on the amount consumed. Inhaling or sniffing wasabi vapor has an effect like smelling salts, a property exploited by researchers attempting to create a smoke alarm for the deaf. One deaf subject participating in a test of the prototype awoke within 10&nbsp;seconds of wasabi vapour sprayed into his sleeping chamber.<ref>{{cite web |title=Wasabi Silent Fire Alarm Alerts the Deaf with the Power of Scent |url=http://inventorspot.com/articles/wasabi_silent_fire_alarm_alerts__11514 |publisher=InvestorSpot |author=Levenstein, Steve |access-date=9 August 2016 |archive-date=10 March 2016 |archive-url=https://web.archive.org/web/20160310144126/http://inventorspot.com/articles/wasabi_silent_fire_alarm_alerts__11514 |url-status=dead }}</ref> The [[List of Ig Nobel Prize winners#2011|2011 Ig Nobel Prize in Chemistry]] was awarded to the researchers for determining the ideal density of airborne wasabi to wake people in the event of an emergency.<ref>{{cite web |title= Winners of the Ig® Nobel Prize: 2011 |website=Improbable Research |date=August 2006 |url=https://www.improbable.com/ig/winners/#ig2011 |access-date=22 March 2019 }}</ref>