The yellowing of broccoli florets is mainly due to the loss of magnesium ions contained in its chlorophyll after too long a preservation period. However, such broccoli, taste and nutritional value of the change is not great, can be consumed normally, like spinach, celery, etc. also have this phenomenon.
Broccoli is rich in nutrients, broccoli mineral composition than other vegetables more comprehensive, calcium, phosphorus, iron, potassium, zinc, manganese and other content is very rich, than the same belongs to the cruciferous family of cabbage flower is much higher. Vitamin C content is about 20% higher than cabbage flower, 2-3 times the cabbage, 5-6 times the tomato; carotene content is more than 30 times the cabbage flower; folic acid content is 2 times the cabbage flower; protein content is 3 times the cauliflower, 4 times the tomato.