To explore the effects of freeze-thawing on the physicochemical properties of different muscle types during refrigeration storage

the white and red muscles of spotted silver carp were studied. The water retention (drip loss

water activity

and water distribution)

color

protein thermal stability

and texture of muscle were analyzed under direct refrigeration storage (4 ℃ stored for seven days) and freeze-thaw refrigeration storage (frozen at -18 ℃ for one day

stored at 4 ℃ for six days after thawing). The results showed that the drip loss of muscle increased significantly during freeze-thaw storage. After freeze-thawing

the changes in the relaxation time

the peak area percentage of immobilized water

and free water in white muscle were more apparent than those in red muscle. Freeze-thawing significantly increased the lightness value L* of white muscle

and the yellow value b* of red muscle increased by 104%. In addition

the stability of protein structure was related to the muscle type

and freeze-thawing aggravated the decrease of myosin enthalpy. In addition

the hardness and chewiness of muscle decreased significantly during storage

and the white muscle was more prone to dry consumption after freeze-thawing. Therefore

red muscle fibers may have better freeze tolerance

and freeze-thawing may have less effect on the physicochemical properties of red muscle.