Broccoli is mainly composed of cell walls, which are mainly composed of cellulose and hemicellulose. These cellulose and hemicellulose are important components of plant cell wall, which makes the fiber of broccoli hard, so cooking takes 5 to 7 minutes. Broccoli, also known as broccoli, broccoli or American cauliflower, is an annual or biennial herb of Brassica in Cruciferae. It originated in Italy on the Mediterranean coast of western Europe, and looks like a flower, so it is called broccoli. Its taste is crispy, its nutritional value is high, and it is rich in antioxidant substances such as vitamin C and proanthocyanidins, and it is known as the queen of vegetables.