| With the frozen aerated emulsion system containing coffee as subject, the pea protein isolate with pH-shifting treatment, ultrasonic treatment and their combination were applied to the emulsion system,the physicochemical properties and fat crystallization behavior of the emulsion before and after whipping were determined to analyze the effect of the modification of pea protein on the coffee frozen aerated emulsion system. The results showed after pH-shifting and ultrasonic treatment, the particle size of the emulsions decreased, the viscosity increased, and more dense fat clusters could be observed in emulsions, which would promote the puncture of fat crystals in the droplets leading to partial coalescence of fat and facilitating the retention of bubbles. After whipping, the expansion rate of emulsion stabilized by proteins treated by pH-shifting, ultrasonic and their combination increased from 32.49% to 55.04%, 45.07%, and 63.97%,respectively, and had better shape retention, which indicated that the emulsions formed a good three-dimensional fat network structure after whipping, inhibited the migration of fat crystals, and improved rheological properties. Smaller ice crystals were formed in emulsions after pH-shifting and ultrasonic treatments and the texture of emulsions got finer，and the quality of the frozen aerated emulsion obtained by the combination treatment of pea protein was the best. |
