Techno-functionality of pea protein isolate: Influence of ultrasound and high-pressure homogenization modification...

Pea protein isolate (PPI) was modified using high-pressure homogenization (HPH) at three pressure levels (60, 80, and 100 MPa) for three cycles and ultrasound (US) at three power levels (100, 200, and 300 W) for 10 min. Results showed that both techniques significantly increased solubility, oil holding capacity, emulsifying activity and foam capacity. Ultimately, a homogenization pressure of 100 MPa (HPH 100) and an ultrasound power of 300 W (US 300) were identified as the optimal treatments. HPH and US treatments led to a significant reduction in particle size and an increase in the surface charge of the samples. FTIR spectroscopy revealed changes in hydrogen bonding and the secondary structure of PPI after HPH and US treatment. Also, SEM imaging showed that the spherical shape of PPI transformed into heterogeneous sheet structures. Additionally, the comparison of HPH and US techniques revealed that the HPH resulted in a greater reduction in size and a greater increase in solubility and FC compared to the US. On the other hand, the US technique showed greater EAI and thermal stability. Therefore, both HPH and US are effective in altering the PPI structure to enhance its functional properties.