Fire Aspect adds 80 fire-ticks (4 seconds of burning) per level to the target. Because the first hit is caused by the item with this enchantment, the first second of fire damage is not recognized. Targets receive 3 and 7 damage with level I and II respectively.
When a mob that normally drops meat is killed while burning, it drops cooked meat. Experience is dropped only if non-fire damage was dealt by the player within 5 seconds of the death.