Abstract: Potato protein deaminated for different durations (0, 0.5, 3, 6 and 12 h) were used to prepare emulsions, and the products obtained were evaluated for droplet size distribution, emulsion stability, microrheological properties and microstructure. The results showed that the droplet volume mean diameter and Turbiscan stability index (TSI) of the emulsion decreased first and then increased with increasing deamidation time. The emulsions with potato protein deaminated for 3 and 6 h exhibited uniform droplet size distribution and good stability, which may be because the increased electrostatic repulsion between the modified protein emulsion droplets prevented their aggregation. The droplet size of the emulsion with potato protein deaminated for 12 h increased and the stability decreased, which may be because of the decreased charge repulsion force and consequent droplet aggregation. The microrheological analysis showed that the emulsion with potato protein deaminated for 6 h had the highest macroscopic viscosity index (MVI) value and the highest viscosity, and the speed of droplet movement was slowed down. There was a strong force between the emulsion droplets, which made the system more stable. This study can provide a reference for further research and development of potato protein products in order to improve the utilization rate of potato protein and expand the application range.

Key words: potato protein; deamidation; emulsion; microrheological properties