Broccoli

What part of the plant?

Broccoli’s edible head is the immature flower bud cluster of the plant, harvested before the buds open into yellow flowers. If left in the garden too long, the buds bloom and the head loses its tight, dense form — and most of its sweetness.

A descendant of cabbage

Broccoli, cauliflower, kale, kohlrabi, Brussels sprouts, and cabbage are all the same species — Brassica oleracea. Each is a different cultivar, selectively bred over centuries to emphasize a different part: stems (kohlrabi), leaves (kale and cabbage), buds (broccoli), or sprouts (Brussels).

The Romans cultivated broccoli’s ancestor; today’s form developed in 6th-century-BCE Italy and was exported north in the 16th century. It only became common in American kitchens after Italian immigrants brought it to California in the 1920s.

Sulforaphane

Broccoli contains glucoraphanin, which converts to sulforaphane when the vegetable is chopped or chewed. Sulforaphane has been studied extensively for its anti-inflammatory and possibly anti-cancer effects, particularly in cruciferous vegetables.

Cooking note

Brief cooking — 3 to 5 minutes of steaming — preserves vitamin C and the bright green color. Overcooking releases sulfur compounds that produce the unpleasant smell often associated with cafeteria broccoli.