Abstract: Freezing is one of the oldest and most widely used preservation methods for maintaining meat quality and safety. However, during the production, storage, sale and consumption processes, frozen meat will constantly undergo the freezing and thawing process due to the imperfect cold chain system and eating habits. The recrystallization of ice crystals during freeze-thaw cycles leads to cellular contraction and ultrastructural damage, induces and accelerates fat hydrolysis, lipid oxidation, protein oxidative denaturation, conformational changes, and spatial reorganization, seriously affects the stability of the meat system, and causes a series of problems such as the decline of meat quality and the loss of commercial value. Therefore, this review comprehensively examines the effects of freeze-thaw cycles on key quality attributes of raw meat, including color, tenderness, water-holding capacity, lipid oxidation, protein oxidation and degradation. Furthermore, it summarizes and compares the principles, effectiveness, and limitations of current techniques for identifying frozen-thawed meat including enzyme-based, DNA fragmentation-based, bioimaging-based, and spectroscopic techniques. Special emphasis is placed on the application of spectroscopic techniques-specifically Raman spectroscopy, infrared spectroscopy, and hyperspectral imaging-for identifying frozen-thawed meat. This review aims to provide theoretical foundations and research perspectives for enhancing the quality control of frozen meat and developing novel technologies for identifying frozen-thawed meat.

Key words: freeze-thaw cycles; raw meat quality; frozen-thawed meat; spectroscopic technique