Synergistic Effects of Ultrasound and Chia Seed Oil on Yak Myofibrillar Protein Gelation: Structure and Gel Property

The scope of this paper is to investigate the effects of chia seed oil (CSO) ultrasound treatment as a green improvement method for yak myofibrillar protein (MP). We investigated the effects of different concentrations of CSO (0, 1.5, 3.0% w/w) combined with different ultrasonic power levels (0, 40, 80, 120 W) on the structural and gel properties of yak MP. The CSO-MP system remained stable as an oil-in-water emulsion during testing, with ultrasound serving as the key technique for preparing it. For the moderate ultrasound, CSO significantly increased MP solubility, whiteness, and gel strength, while significantly reducing cooking loss (CL) (p < 0.05). Compared with the control group (U0C0), the solubility, whiteness, and gel strength increased by 156.25%, 7.54%, and 89.11%, respectively, while the turbidity, centrifugal loss, and CL decreased by 51.70%, 64.90%, and 32.73%, respectively. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), secondary structure, gel rheological properties, water distribution, and SEM microstructure indicated that moderate ultrasound CSO treatment enhanced the intensity of the myosin heavy chain (MHC) band and the proportion of α-helix and endowed the MP gel with excellent textural properties and water retention. During the ultrasound, CSO (80 W, 3.0%) significantly improved the structural and gel properties of MP.