Curing salt at 100ppm level in ring. Heated in 225F electric oven. Slices removed as temperature measured just below surface rose in 10F increments:
Cooked in 225F pellet smoker
Brisket forms a more stable ring at a lower temperature than pork. This is partly due to higher myoglobin levels in brisket, and perhaps the difference in myoglobin chemistry. Also note the ring is darker where the meat dries out earliest (typically on the edges cut across the grain).