Physicochemical and Antioxidant Properties of Industrial Hemp Seed Protein Isolate Treated by High-Intensity Ultrasound.

Ultrasound is one of the non-thermal, green, and novel technologies used to functionalize plant proteins. We recently determined the optimum conditions of high-intensity ultrasound (HIUS) treatment for maximum solubility and investigated the functional properties of hemp seed protein isolate (HSPI) under the optimal conditions. In this study, we analyzed changes in primary, secondary, and tertiary structures, physical microstructures, thermal stability, and antioxidant capacity of ultrasound-applied hemp protein isolate (HSPI-HIUS). The free SH group content (+59%) and zeta potential (+25%) increased upon ultrasound treatment. The electrophoretic protein patterns of HSPI showed no significant change after HIUS treatment. The FTIR spectrum revealed the wavenumber shifts in Amid 1 and 2 regions of protein. The denaturation temperature and the ratio of β-structure increased after sonication. Antioxidant properties of hemp seed protein isolates were increased by 38% by ultrasound treatment. The obtained data in this study showed that HIUS treatment would be promising for improving the functional, physicochemical, and antioxidant properties of HSPI.