Eutrema japonicum (Miq.) Koidz. - syn. Wasabia japonica (Miq.) Matsum.; Eutrema wasabi Maxim.; Cochlearia wasabi Siebold - Brassicaceae \\
Japanese horseradish, **Japanischer Meerrettich**, Wasabi

Perennial herb, up to 60cm tall, native to Japan, Korea, Sakhalin, cultivated in Japan, Korea and Taiwan for its edible rhizomes (source of the pungent condiment, wasabi). \\
[[http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=241000220]]

"Its stem is used as a condiment and has an extremely strong flavor. Its hotness is more akin to that of a hot mustard than that of the capsaicin in a chili pepper, producing vapours that stimulate the nasal passages more than the tongue." [[http://en.wikipedia.org/wiki/Wasabi]]

Fresh wasabi paste made by crushing the root develops a characteristically fresh greenish flavor clearly different from the flavors of pastes from the other glucosinolates containing plants. LC/GC/MS/1H-NMR showed 6-methylthiohexyl isothiocyanate (2mg/kg), 7-methylthioheptyl isothiocyanate and 8-methylthiooctyl isothiocyanate to be the characteristic greenish wasabi flavor components. \\
[ω-Methylthioalkyl isothiocyanates in Wasabi. Agricultural and biological chemistry, INA, Kazuo, et al., Vol.53, 1989, 537-538]

The rhizome contains most of the flavour and is the part most widely used, although both the leaves and petioles contain some of the flavour. Wasabi myrosinase liberates a mixture of isothiocyanates from precursor molecules, giving wasabi its distinctive flavour. \\
[Flavour and pharmaceutical properties of the volatile sulphur compounds of Wasabi (//Wasabia japonica//). Depree, J.A., Howard, T.M., Savage, G.P., Food research international, 31(5), 1998, 329-337]

The main volatile components of E.wasabi grown in Yunnan were identified as 1,6-hexane diisothiocyanate (30.7%) and allyl isothiocyanate (17.1%)  with GC-MS. \\
[Study on Volatile Components Of Yunnan Eutrema Wasabi Maxim., LU, Li-he, et al. Yunnan Chemical Technology, Vol.5, 2011, 4]

Total content of isothiocyanates of Japanese horseradish rhizome grown in New Zealand was 2067mg/kg fresh weight, with allyl isothiocyanate (AITC, 1937 mg/kg) as the main component. Minor components present were 3-butenyl isothiocyanate (43 mg/kg), 4-pentenyl isothiocyanate (47 mg/kg), sec-butyl isothiocyanate (18 mg/kg), isopropyl isothiocyanate (12 mg/kg) and 5-hexenyl isothiocyanate (7 mg/kg). \\
[Comparison of flavour compounds in wasabi and horseradish., Sultana, T., Savage, G. P., McNeil, D. L., Porter, N. G., Clark, B., Journal of Food Agriculture & Environment, Vol.1(2), 2003, 117-121] [[http://www.coppersfolly.co.nz/v1/research/comparison2.pdf]]

| {{:allylitc.jpg|allyl isothiocyanate}} \\ allyl isothiocyanate \\ //(pungent mustard)// | {{:octa15diene3one.jpg|(Z)-octa-1,5-dien-3-one}} \\ (Z)-octa-1,5-dien-3-one \\ //(green geranium)// | {{:3methyl24nonandione.jpg|3-methyl-2,4-nonanedione}} \\ 3-methyl-2,4-nonanedione \\ //(fruity hay)// | {{:pyrazine_2meo3isopropyl.png|2-methoxy-3-isopropylpyrazine}} \\ 2-methoxy-3-isopropylpyrazine \\ //(earthy green)//| {{:3r4r3methyl4decanolide.jpg|(3R,4R)-3-methyl-4-decanolide}} \\ (3R,4R)-3-methyl-4-decanolide \\ //(lactonic green)// | 

"Freshly grated wasabi aroma was investigated by aroma extract dilution analysis. At the highest flavor dilution factors of 1024 and 256, ten odorants were detected as odor-active compounds: allyl isothiocyanate, (Z)-1,5-octadien-3-one, 4-pentenyl isothiocyanate, 5-hexenyl isothiocyanate, 3-methyl-2-butene-1-thiol, 2-isopropyl-3-methoxypyrazine, 3-methyl-2,4-nonanedione, cis-3-methyl-4-decanolide, 6-(methylthio)hexyl isothiocyanate, and vanillin. To determine the absolute configuration of cis-3-methyl-4-decanolide in wasabi, the stereoisomers of 3-methyl-4-decanolide were synthesized from optically active γ-decalactone. Finally, the absolute configuration of cis-3-methyl-4-decanolide in wasabi was determined as (3R,4R)-3-methyl-4-decanolide by chiral GC-MS. Sensory analysis revealed that the (3R,4R)-3-methyl-4-decanolide constitutes an essential part of fresh wasabi aroma." \\
[Nakanishi, Akira, et al. "(3R,4R)-3-Methyl-4-decanolide, a Novel Lactone Contributing to Fresh Wasabi (Wasabia japonica) Aroma." Importance of Chirality to Flavor Compounds. American Chemical Society, 2015. 99-108]

Synthesis of both enantiomers of cis-3-methyl-4-decanolide showed that the (3R,4R) isomer has a lactonic-fatty top note and a lactonic-green middle note. \\
[Masuzawa, Yoko, Shigeyuki Tamogami, and Takeshi Kitahara. "Synthesis of both enantiomers of cis-methyl-4-decanolide, a key component for the scent of African orchids." Natural Product Letters 13.4 (1999): 239-246]

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"The main bioactive compound of wasabi is 6-MSITC (6 methylsulfinyl hexyl isothiocyanate), which has anti-oxidant and anti-inflammatory functions. Anti-oxidants and anti-inflammatories have an important role in cognitive health. Therefore, 6-MSITC is expected to have positive effects on cognitive function. Previous studies showed the beneficial effects on cognitive functions in middle-aged adults. However, it is unclear that 6-MSITC has a positive effect on cognitive functions in healthy older adults aged 60 years and over. Here, we investigated whether 12 weeks’ 6-MSITC intervention enhances cognitive performance in older adults using a double-blinded randomized controlled trial (RCT). Methods: Seventy-two older adults were randomly assigned to 6-MSITC or placebo groups. Participants were asked to take a supplement (6-MSITC or a placebo) for 12 weeks... We found two main findings. First, the 6-MSITC intervention improved working memory capacity as measured by DS-B compared to the placebo group. Second, the 6-MSITC intervention improved episodic memory performances as measured by LM and FSM. ... This study firstly demonstrates scientific evidence that 6-MSITC may enhance working memory and episodic memory in older adults. We discuss the potential mechanism for improving cognitive functions after 6-MSITC intake." \\
[Nouchi, Rui, et al. "Benefits of Wasabi Supplements with 6-MSITC (6-Methylsulfinyl Hexyl Isothiocyanate) on Memory Functioning in Healthy Adults Aged 60 Years and Older: Evidence from a Double-Blinded Randomized Controlled Trial." Nutrients 15.21 (2023): 4608]

{{:wasabia_japonica.jpg}} \\
Wasabia japonica, Aizu area, Fukushima pref., Japan \\ 
Author: Qwert1234[[https://creativecommons.org/licenses/by-sa/3.0/de/|CC BY-SA 3.0]]    [[https://commons.wikimedia.org/wiki/File:Wasabia_japonica_1.JPG|Wikimedia Commons]]