Application of ultrasound-assisted alkaline extraction for improving the solubility and emulsifying properties of pale, soft, and exudative (PSE)-like chicken breast meat protein isolate

The effect of ultrasound-assisted alkaline extraction (UAE) for different times (0, 5, 10 or 15 min) on the structure, solubility and emulsifying properties of pale, soft, and exudative (PSE)-like chicken breast meat protein isolate (PPI) was investigated. UAE did not change the composition of PPI. UAE significantly increased both the alpha-helix and beta-turn content of PPI and changed the tertiary structure, which indicated that UAE recovered the secondary structure of PPI and promoted the unfolding of protein. The solubility, emulsifying activity index and emulsifying stability index of PPI were all enhanced, especially UAE for 10 min, increasing by 50.14%, 20.25% and 5.59%, respectively. The emulsion fabricated with PPI obtained by UAE had a lower interfacial tension. The droplet size and distribution, optical microscopy and cryo-scanning electron microscopy confirmed that the UAE-treated PPI stabilized emulsion showed a smaller size and more uniform distribution. Raman spectroscopy of the PPI stabilized emulsions revealed that the content of alpha-helix and in the emulsion prepared with PPI treated by UAE significantly increased, which was beneficial to form a more stable emulsion. UAE can be applied to change the PPI conformation and improve its emulsion stability to expand the effective utilization of PSE-like chicken meat.