Effect of multi-frequency ultrasound-assisted immersion freezing on quality changes in large yellow croaker (Larimichthys crocea) during frozen storage

The effects of multi-frequency ultrasound-assisted immersion freezing (MUIF) at different ultrasound power levels (160, 175, and 190 W, respectively) on the quality of large yellow croaker (Larimichthys crocea) during frozen storage were studied. The study found that water loss and texture deterioration of MUIF were lower and MUIF was fresher than immersed freezing (IF) by affecting the morphology of ice crystals. Although the total volatile basic nitrogen (TVB-N) and K values of each treatment increased continuously during frozen storage, MUIF was consistently lower than IF. Among them, MUIF at 175 W (MUIF-175) maintained good quality in frozen storage because of the fine and uniform ice crystals, indicating that MUIF at a specific power level can reduce the quality degradation of the samples during frozen storage.