Tatsoi

fast-growing, vigorous mild mustard forming a rosette of deep green savoyed leaves.

ready in 25 days as baby leaf, 45 days full size. the flowers attract beneficial insects when left to bolt.
young leaves are mild and sweet, older leaves develop that mustard bite.

the moment you chew, cut, or damage the leaf, a separate enzyme called myrosinase is released from ruptured cell walls and immediately reacts with the glucosinolates — converting them into isothiocyanates (ITCs). the plant designed this as a pest defense system. what it accidentally made was one of the most studied classes of cancer-preventive compounds in human nutrition.

sulforaphane, BITC, and PEITC have been studied against breast, brain, blood, bone, colon, gastric, liver, lung, oral, pancreatic, and prostate cancers. the mechanism across all of them involves activating Nrf2 (the master antioxidant transcription factor), inducing cancer cell apoptosis, triggering ROS production specifically in cancer cells, and blocking cell cycle progression.
isothiocyanates derived from brassica glucosinolates are bioactive organo-sulfur compounds with antioxidant, anti-inflammatory, antimicrobial, and anticancer properties. the key ITCs are sulforaphane, benzyl isothiocyanate (BITC), and phenethyl isothiocyanate (PEITC) — all present across Brassica rapa varieties.

raw or lightly cooked is the move. myrosinase is heat-sensitive. heavy cooking destroys the enzyme and kills the glucosinolate-to-ITC conversion. chewing activates more myrosinase activity than swallowing whole. the mild mustard bite you taste when eating Brassica Rapa raw is literally the ITC reaction happening in your mouth. eating it raw or quickly sautéed preserves the most bioactive load.