Broccoli

Broccoli (Brassica oleracea var. italica) is an annual or biennial herb of the mustard family (Brassicaceae), 40–80 cm tall, with an erect branched stem. The main head at the top is a dense mass of dark-green immature florets, 10–20 cm across; after cutting, many smaller side heads form from the leaf axils. The leaves are large, oval, deeply lobed, grey-green, long-stalked; like cauliflower but with greener, looser heads. Left too long, small four-petalled yellow flowers open and round brown seeds form. The head and young stems are edible, neat and crisp, mildly sweet.

Broccoli comes from Italy (southern Europe), selected from wild cabbage since Roman times; today it is grown across Europe, North America and East Asia. In Vietnam it is a winter-spring crop of cool areas (Da Lat, the Highlands, northern lowlands), used boiled, garlic-stir-fried, steamed, in soups, hotpot and pan-fried. Broccoli is rich in vitamins C, K and A, folate and fibre; it contains glucoraphanin which converts to sulforaphane when cut or chewed — an isothiocyanate with strong antioxidant activity, studied for cardiovascular and cancer prevention. It is a recommended vegetable in a healthy diet.