New insights into the mechanism of freeze-induced damage based on ice crystal morphology and exudate proteomics

To get insight into freeze-induced damage in meat, researchers evaluated the formation of ice crystals in the initial freezing stage and the protein profile and bioinformatics information in thawed exudates. Two treatments were used with high freezing temperatures of -12 °C and low freezing temperatures of -80 °C. Lower-temperature (-80 °C) freezing benefits small, evenly distributed intracellular ice crystals and causes less damage to muscle fibers. 82 proteins were identified as differentially abundant proteins (DAPs) based on the data-independent acquisition (DIA) techniques. Most of these proteins were binding proteins, oxidoreductases, transferases, and protease inhibitors that were involved in oxidative phosphorylation, glycolysis, the tricarboxylic acid cycle (TCA), amino acid metabolism, and other pathways. Seven proteins were screened as potential markers of exudates. Besides the mechanical damage caused by ice crystal formation, we postulated that ATP decomposition causes muscle contraction during freezing and thawing. Furthermore, the effect of CAST on calpain activity reduces proteolytic capacity, which is also one of the reasons for decreased muscle quality. These results could add to what is already known about how frozen meat deteriorates, which could help control the quality of frozen meat and develop new technologies.