Ultrasound thawing for improving the eating quality and off-flavor of frozen duck meat and its possible mechanisms

The aim of this study was to investigate the effect of ultrasound thawing on the eating quality and off-flavor of frozen duck meat and discuss its possible mechanisms. The thawing rate, meat quality, Low-field nuclear magnetic resonance (LF-NMR), secondary structure, free amino acid (FAA) and volatile flavor compounds under different ultrasound thawing power (0, 200, 400, and 600 W) were determined. The results showed that ultrasound powers ranging from 200 W to 600 W significantly shortened the thawing time by 30.96%–55.05%. Compared to the control group without ultrasound treatment, 400 W ultrasound thawing significantly reduced (P < 0.05) thawing loss, pH, L*, b*, shear force and pressure water loss, and increased a*, ΔE, and BI, indicating an improvement in color, tenderness, and water holding capacity (WHC). LF-NMR and Raman spectra analyses demonstrated that 400 W ultrasound thawing effectively reduced the loss of free water and promoted the α-helix to β-sheet transition, thereby improving the WHC. Moreover, the off-flavor compounds of duck meat were effectively reduced by inhibiting lipid oxidation and FAA degradation in 400 W ultrasound thawing group. These findings provide a new perspective on the reduction of off-flavor and optimizing ultrasound thawing power of frozen duck meat.