Researchers have long tried to determine the extent of protein loss caused by cooking chicken. As far back as 1946, Dr. C. P. Stewart of the Royal Infirmary in Edinburgh determined that boiling does destroy more meat protein than steaming or roasting, but he had trouble assessing the practical importance of the loss. More recently, the National Broiler Council has maintained that the amount of protein remains basically the same regardless of cooking methods, and a 2000 study at the University of Arkansas concluded that the extent of loss depends more on cooking temperatures than on cooking technique.
Effects of Temperature
All forms of cooking destroy some soluble proteins, and the extent of the loss depends largely on the temperature at which the meat is cooked. Exposure to temperatures of 104 degrees F decreases soluble protein by 9.7 percent, while cooking at 176 degrees F results in a 89.7 percent loss with respect to the protein in raw chicken. Some myofibrillar proteins in chicken undergo changes due to heat. The higher the temperature, the greater the water loss and denaturation, which results in shrinkage of muscle fiber, increased cook loss and changes in texture.
Importance of Cooking
You may feel tempted to under-cook chicken to preserve protein, but cooking is an essential aspect of food safety. Heating chicken prevents food-borne illness, and it also aids digestion. Higher temperatures increase the kinetic energy within protein molecules. This disrupts the bonds within protein chains by causing them to vibrate violently, and is called denaturation. The denaturation process uncoils proteins into a random shape, resulting in changes to the physical and chemical structure of the meat. The proteolytic enzymes in your digestive system are better able to break these chains down into their component amino acids, which your body can then use.
The greater the temperature, the greater the protein loss. Since raw or undercooked chicken is generally unsafe, do not attempt to eat it unless thoroughly cooked. Boiling requires temperatures of at least 212 degrees F and other cooking methods may employ even higher heat, but ground chicken is safe to eat at 165 degrees F and chicken breasts are safe at 170 degrees F. A slow cooker can cook chicken thoroughly at temperatures as low as 170 degrees F, but is not as fast or convenient as high-temperature cooking methods. To determine your ideal cooking method, decide if higher protein content is more important to you than speed and convenience.
Many factors influence the net protein loss associated with cooking meat. The type of meat is also important. Organ meats, such as kidneys, lose far more protein during cooking than the muscle meat in a chicken breast. Frying results in a smaller net loss of protein, because the protein from eggs, milk and other batter ingredients offsets the loss of meat protein. Frying is generally less healthy than boiling because fried chicken is higher in fat.
- Poultry Science; Effect of Meat Temperature on Proteins, Texture, and Cook Loss for Ground Chicken Breast Patties ; R. Murphy and B. Marks
- Journal of Food Science; Changes in Chicken Muscle Proteins During Cooking and Subsequent Frozen Storage, and Their Significance in Quality; A. Khan and L. Van Den Berg
- Elmhurst College: Virtual Chem Book: Denaturation of Proteins
- Encyclopedia Britannica: Proteolytic Enzyme
- Proceedings of the Nutrition Society; Loss of Nutrients in Cooking; C. P. Stewart
- Chicago Tribune; No Protein Lost When Chicken Is Boiled -- But Fat Melts Away; Phyllis Magida
- Yale Medical Group: Recommended Temperatures for Safe Cooking
- National Weather Service Forecast Office: Fahrenheit to Celsius Converter
- USDA Food Safety and Inspection Service: Slow Cookers and Food Safety