Ultrasound-Assisted Salt Penetration in Sauced Duck: Insights from LF-NMR and MRI Combined Analysis

This study investigated the effect of ultrasound-assisted curing on salt penetration in sauced duck using a combination of low-field nuclear magnetic resonance (LF-NMR) and magnetic resonance imaging (MRI). Ultrasound treatment significantly accelerated salt penetration in duck meat during curing. The salt content of ultrasound-treated samples at 150 W, 300 W, and 450 W was 2.56 ± 0.08%, 2.84 ± 0.02%, and 3.52 ± 0.02%, respectively, significantly higher than that of the untreated control 2.17 ± 0.09%. Moreover, the enhancing effect on salt uptake increased with ultrasound power. Notably, treatment with 28 kHz, 450 W ultrasound resulted in a salinity comparable to that achieved by traditional curing 3.46 ± 0.11%. To further assess salt distribution, LF-NMR and MRI were employed, providing non-destructive, rapid, and precise visualization of salt penetration. Pseudo-color images confirmed the salt content results and revealed that the 28 kHz, 450 W ultrasound treatment promoted a more uniform salt distribution, similar to conventionally marinated samples. These findings indicate that the combined use of LF-NMR and MRI is a promising approach for characterizing and monitoring salt penetration in duck meat. Overall, this study provides valuable insights for improving and controlling the quality of highly processed meat products.