Wasabi (Japanese Horseradish) Paste and Seasoning

Wasabi (Eutrema japonicum) is a Brassicaceae rhizome cultivated in cold flowing spring water — the production conditions limit commercial supply to a small number of Japanese regions (Shizuoka Izu, Utogi; Nagano Azumino; specialty sites in other prefectures). The fresh rhizome is grated to release the isothiocyanate flavour compounds responsible for the characteristic sharp aroma.

Mixed-formula wasabi paste — the dominant commercial product in the tube category — typically combines Western horseradish (Armoracia rusticana, which contains similar isothiocyanates at higher concentration), seasonings, and food colouring (chlorophyllin or other approved green colorants). JAS labelling requires the proportion of true wasabi to be disclosed; pure-wasabi paste (本わさび使用 / 本わさび 100%) is positioned as premium and commands 5–10× the standard product price.

In Japanese seasoning OEM, wasabi paste appears as tube-pack retail (the volume category — the standard household sushi / sashimi accompaniment); as pure-wasabi paste premium SKUs from Shizuoka and Nagano (with prefectural geographical indication or specified-producer labelling); as wasabi powder for foodservice supply and dip-mix OEM; as the ingredient in wasabi-flavoured snack OEM (wasabi-peas, wasabi-rice-cracker the volume snack categories); and as the ingredient in wasabi-mayonnaise dressing and dip OEM.

The commercial split between pure-wasabi and mixed-formula product is sharp. Pure-wasabi positioning is mandatory for sushi-grade restaurant supply, gift packaging, and Shizuoka / Nagano regional brand SKUs. Mixed-formula product supplies the household retail volume and foodservice mass-market segment.

Wasabi paste is regulated as a compound seasoning under the Food Sanitation Act and JAS labelling standards. JAS regulations require disclosure of the wasabi proportion versus Western horseradish content; mis-labelling pure-wasabi when the product is mixed-formula is subject to enforcement under the Food Labelling Act.

Some functional positioning of wasabi (anti-microbial, digestive support) is submitted under the Foods with Functional Claims framework; ordinary labelling cannot make therapeutic claims about isothiocyanates without notification.