Is Myoglobin the Same in all Meats?
Some meats have more myoglobin than others. Example: Beef has more myoglobin than pork, which in turn has more than poultry. Even in the different cuts of meat, some meat cuts have more myoglobin than others.
What Causes a Smoke Ring To Form?
When the wood combusts, it releases traces of Nitric Oxide (NO) and Carbon Monoxide (CO), which react with myoglobin upon contact. This reaction prevents the myoglobin from changing its pink color. This is because Nitric oxide will bind about 100,000 times tighter to the myoglobin than oxygen will. Carbon monoxide will bind about 2 times tighter to myoglobin than oxygen will.
This results in a pink-colored ring across the meat’s cross-section, which we know as barbecue smoke rings.
But why is the smoke ring only about ⅛” to ½” thickness around the edges? This is because the molecules CO and NO cannot penetrate to meat any further before the meat heats up, turning the center of the meat into an irreversible brown/gray color.
You can increase the smoke ring thickness by controlling a few factors in the barbecue smoking process.