Fresh keeping mechanism of Fenneropenaeus chinensis by ultrasound‐assisted immersion freezing: Effects on microstructure and quality changes.

The fresh keeping ability of ultrasound‐assisted immersion freezing (UIF), immersion freezing (IF), and refrigerator freezing (RF) was compared in Fenneropenaeus chinensis (F. chinensis). Observation of muscle microstructure indicated that UIF treatment had the smallest ice crystals formation with uniform distribution, resulting in minimal damage to muscle tissues. Meanwhile, UIF‐treated F. chinensis showed slower pH change, lower values of total volatile basic nitrogen (TVB‐N), and thiobarbituric acid reactive substances (TBARS). The higher values of salt soluble protein content，Ca2+‐ATPase activity, and water‐holding capacity revealed that UIF could inhibit protein degeneration and moisture loss. In addition, an excellent sensory evaluation score also verified the efficient fresh keeping capacity of UIF. Our results indicate the potential of UIF in maintaining the freshness and quality of F. chinensis during frozen storage. Novelty impact statement: Preservation effects of different freezing methods to Fenneropenaeus chinensis were compared.Ultrasound‐assisted immersion freezing caused less tissue damage to shrimp and could inhibit the spoilage during frozen storage.Ultrasound assistance is efficient for the fresh keeping of aquatic products. [ABSTRACT FROM AUTHOR]