Dual-frequency ultrasound-assisted thawing: enhancement on quality attributes, myofibril characteristics, and microstructure of large yellow croaker (Pseudosciaena crocea) during frozen to refrigeration

Emerging non-thermal technologies are widely applied in storage and processing of aquatic products, especially ultrasound-assisted technology. Frequency is an important component of ultrasound, and the effects of different ultrasound frequencies are obviously different. This research evaluated the effects of single-frequency (28 kHz, 40 kHz) and dual-frequency (28/40 kHz) ultrasound-assisted thawing (UAT) treatment on physicochemical quality, myofibril characteristics, and microstructure of large yellow croaker during frozen to refrigeration. The results revealed that UAT treatment retained a better performance, such as water-holding capacity (WHC), color, texture, and water distribution, and relieved disruption of microstructure, especially DUAT-28/40 treatment. The total volatile basic nitrogen (TVB-N) obtained the most desirable freshness property under the DUAT-28/40 treatment, as well as the free amino acids analysis. In addition, it reduced the myofibril denaturation during frozen to refrigeration, as shown in protein primary structure, infrared detection, and fluorescence intensity analysis. Therefore, DUAT-28/40 treatment could be a possible thawing method for relieving the quality deterioration of large yellow croaker during frozen to refrigeration.