Ultrasound Thawing Enhances Myofibrillar Protein Integrity and Quality Attributes of Common Carp (Cyprinus carpio) Fillets.

Freezing and thawing are critical techniques for preserving seafood quality and extending shelf life. This study evaluated the effects of ultrasound-assisted (UT), water immersion (WT), and microwave (MT) thawing on physicochemical, textural, and structural quality attributes of common carp (Cyprinus carpio) fillets and their myofibrillar protein properties. Results demonstrated that ultrasound thawing (UT) most effectively maintained pH and minimized protein aggregation, reducing myofibrillar protein particle size by approximately 49%, significantly lowering turbidity, and decreasing cooking loss by about 10% compared with water immersion thawing (WT). In contrast, water immersion thawing resulted in the greatest moisture loss, whereas ultrasound and microwave thawing better preserved water-holding capacity. Scanning electron microscopy revealed that WT and MT caused minor muscle damage, whereas UT better preserved protein integrity, showing significantly reduced aggregation and higher zeta potential compared with MT (p < 0.05). SDS-PAGE confirmed that no treatments altered the primary protein structure. Based on overall quality retention, ultrasound thawing is recommended as the optimal thawing method for common carp fillets.