Broccoli (Brassica oleracea) one of the world’s most popular vegetables. The green florets are easy to prepare eaten either raw or cooked. Broccoli is a particularly rich source of vitamin C and vitamin K. Con - tents of its characteristic sulfur-containing glucosinolate compounds, isothiocyanates and sulforaphane, are better preserved by steaming, microwaving or stir-frying. Frozen it maintains those nutrients for the longest period.