The toxic substance in yellow cauliflower is colchicine (Colchicine autumnale), a perennial plant of the genus Colchicine, which grows in low-moisture meadows. The whole plant contains colchicine, which is oxidized to colchicine dioxide when ingested, attacking the central nervous and cardiovascular systems, thus causing numbness of the nerves and hemorrhage in internal organs.

It is an alkaloid. It was originally extracted from the stems of the plant colchicine in the lily family and got its name. Pure colchicine appears as yellow needle-like crystals with a melting point of 157°C. It is easily soluble in water, ethanol and chloroform and has a bitter taste.

Preventive measures:

Consumption of fresh cauliflower must first be processed to remove the colchicine, due to the colchicine has a better water solubility, you can fresh cauliflower in boiling water blanch bleach, and then fully soak in water, rinse, so that the colchicine to maximize the solubility of the water, and then cook at this time to ensure safety. Colchicine is not heat-resistant, high heat cooking about 10min can be destroyed.

Reference: Baidu Encyclopedia - Cauliflower Food Poisoning