Synergistic effects of mannoprotein and ultrasound on the interfacial properties, flavor, and structure of yeast protein

To expand the application of yeast protein (YP) in the food industry, the synergistic effects of mannoprotein (MP) and ultrasound (US) treatment were explored to improve its solubility, flavor, and structural properties. Results showed that YP and MP formed YP-MP conjugation in 1:3 (w:w), after reacting with citric acid and sodium bicarbonate for 4 h at room temperature and ultrasonic treatment at 1000 W for 30 min. The YP-MP-US sample achieved a maximum protein yield of 54.82 ± 1.67 %. Furthermore, the protein particle size was reduced from 257.67 nm to 159.33 nm after the treatment, thereby improving its solubility, emulsifying, and foaming capacities. Sensory evaluations, combined with E-tongue, E-nose, and HS-SPME-GC-MS analyses, revealed a significant reduction in the unpleasant yeast flavor of YP (p < 0.05). Additionally, the synergistic treatment had altered the conformation and structure of YP, which were confirmed by the notable increase in β-sheet, free sulfhydryl (-SH) groups, surface hydrophobicity, and intrinsic fluorescence while promoting a looser and finer aggregation microstructure. In conclusion, the synergistic treatment significantly improved protein solubility and flavor, thereby enhancing its processing functionality.