The impact of freezing methods on the quality, moisture distribution, microstructure, and flavor profile of hand-grabbed mutton during long-term frozen storage

[Display omitted] •ULF inhibited microorganisms growth, reduced TVB-N values and lipid oxidation.•ULF could decrease water migration and maintain myofibril integrity.•ULF and LF groups had significantly more volatiles than the CF group.•ULF could achieve high-quality control of HGM during long-term frozen storage. The aim of present study was to investigate the influence of conventional freezing (CF, −18 °C), low-temperaturefreezing (LF, −40 °C), and ultra-low-temperature freezing (ULF, −80 °C) on the quality, moisture distribution, microstructure, and flavor profile of hand-grabbed mutton (HGM) during frozen storage (0, 30, 60, 90, 120, 150 and 180 days). The TPC, TVB-N, and TBARS values increased significantly with prolonged storage, while the moisture content decreased (P