Broccoli ( or broccoli , green cauliflower ) is a species of Brassicaceae , large flowering head , is often used as vegetables . Broccoli is usually prepared by boiling or steaming , but can also be eaten raw as a salad in the appetizer plate of cold cuts .Broccoli contains a lot of Vitamin A , Vitamin C , Vitamin K , fiber , Quercetin . It also contains many nutrients that are resistant cancer as Myrosinase , Sulforaphane , Di - indolyl methane and small amounts of selenium .AntioxidantCoronary Heart DiseaseStomachcancerBroccoli is a favorite dish , however broccoli during processing at high temperatures , many studies have shown that vitamin ingredients especially those that act to prevent cancer is reduced . The reason is that high temperatures will cause inactivation of the enzyme and ESP quality , imbalance of sulforaphane . Moreover, a fixed amount of sulforaphane in broccoli Sulphur add very small , only about 20 % of the total and very easy sulphoraphanes disabled . The rest do not have enough useful elemental sulfur , should not have disease resistance .