Ultrasound combined with post-mortem aging enriches antioxidant peptides in Muscovy ducks

To investigate the impact of ultrasound in conjunction with post-mortem aging on antioxidant peptides in Muscovy ducks, this study was conducted under appropriate ultrasound conditions (20 min, 20 kHz, 1050 W), followed by post-mortem aging at 4 °C for 6, 12, 24,72 and 168 h. The analysis focused on the peptide content and antioxidant activity of Muscovy ducks. The results revealed that the peptide content reached the highest of 14.02 mg/g of meat following 72 h post-mortem aging combined with ultrasound treatment; an increase of 1.20 mg/g of meat of peptides was observed compared with the control. Moreover, the antioxidant activity also reached its peak (DPPH· scavenging efficacy was 47.38%). The sarcomeres almost completely disappeared after ultrasound treatment, the M and Z lines darkened, and the activities of cathepsins B, D, H, and L and calpain proteases increased. Gel filtration chromatography and reversed-phase high-performance liquid chromatography were utilized to isolate the peptides with the most potent antioxidant activity. Nine of the sequenced peptides were deemed reliable. ENHHCCC exhibited the highest antioxidant activity. Therefore, ultrasound in conjunction with post-mortem aging is a promising method to enrich antioxidant peptides in Muscovy duck.