Page 30 - Barbecue Chicken Made Easy

Lately we have noticed that this mishap happens even though the meat is cooked to a safe temperature. What is going on here? Two separate phenomena: Pink juices and pink meat.
Pink juices
Once upon a time clear juices may have correlated with safe meat. Sadly, nowadays, following this morsel of common wisdom can result in either illness or badly overcooked meat.
Pink meat and thin pink juice is due to a pink protein called myoglobin. When myoglobin is cooked the color changes, and meat and juices lose their pink tint. So the question is, at what temperature does myoglobin change color? It turns out that there is no fixed temperature at which this happens because other factors come into play.
We spoke to a research scientist at a major chicken processor who prefers that we not use his name. He explained that the acidity (pH) of the meat is a major factor. “When the muscle is high in pH [low in acid] it takes a much higher temperature to denature the myoglobin. The meat may need to be 170 to 180°F before the myoglobin in breasts is denatured sufficiently to see clear juices. The drumstick and thigh have higher levels of myoglobin and they require an even higher internal temperature to denature it. Typically we cook drums or thighs to 175 to 180°F in our plant to make sure no pink remains.”
Conversely, if the muscle pH is low then the myoglobin is denatured at a lower cooked temperature. This means that one might potentially see clear juices at 150°F and this is not safe.
What causes the pH to be high or low? “Muscle pH fluctuations are typically a function of genes and pre-slaughter stress conditions. Stress may occur during catching, transportation,