cauliflower

Brassica oleracea, the flower head, is used in one recipe here, Palestinian maqluba. There 500 grams are cut into large florets and fried in batches with the eggplant and potato in about 2 cm of oil until deep golden, a step the recipe gives 20 to 25 minutes, then layered into the pot over the onion and tomato. The recipe's description names what the frying is for: the cut edges brown into toasted, nutty notes, in place of the sulphurous smell that boiling brings out of raw cauliflower.

The Journal's note on maqluba explains the switch. Raw cauliflower holds its sulphur in reserve as glucosinolates, which break down only when tissue is cut or chewed and the enzyme myrosinase reaches them. Dimethyl sulfide, one product, is the compound trained tasters describe with the word cauliflower, and boiling promotes exactly those sulfides, the smell of overcooked cabbage. Frying goes elsewhere. The brown edges are the Maillard reaction, first described by Louis Maillard in 1912, in which reducing sugars and amino acids at the dry, hot surface yield colour and a family of toasted, nutty aroma compounds. It is not caramelisation, which needs sugar alone at higher temperatures. A fried floret has also lost water, so its sugars are concentrated rather than leached into a pot.