Biochemical and Quality Changes Occurring During Freezing of Poultry Meat

SUMMARY— Comparative studies on muscle from fresh (unfrozen) and freshly frozen chickens showed that freezing caused small, but detectable changes in eating quality and that changes in muscle proteins during freezing depended on freezing rate. Slow freezing caused a larger loss of drip on thawing, a larger loss of nitrogenous constituents and nucleic acid derivatives to the drip, and a larger loss of water‐holding capacity of meat, than fast freezing. In addition, slow freezing, as compared to fast freezing, increased proteolysis and caused a greater decrease in the adenosine‐triphosphatase activity of myofibrillar proteins. Taste panel comparisons of fresh and frozen chicken meat showed that freezing caused a significant change in the odor of uncooked breast and leg meat and a decrease in tenderness of cooked breast meat. The results suggest that rapid freezing preserves the integrity of muscle proteins to a greater extent than slow freezing.