For the big game wings and cauliflower pizza are on the menu at my house. If you cook with cauliflower, you've probably experienced the brown spots that form on the florets over time, while stored in the refrigerator. The spots are caused by oxidation that occurs while the cauliflower is being stored.
While it's an indication that the veggie is beginning to breakdown (decay), food experts say it's still safe to eat. Simply cut off those parts of the cauliflower and prepare as normal.
This is something I've always wondered about and have even thrown away an entire head of cauliflower over.