Effect of high hydrostatic pressure on the structure, physicochemical and functional properties of protein isolates from cumin (Cuminum cyminum) seeds

The effect of high hydrostatic pressure (HHP) treatment on the structure, physicochemical and functional properties of cumin protein isolate (CPI) was investigated. More aggregates, pores, irregular conformations and bigger particle size were observed for HHP-treated CPI. HHP resulted in an increase in alpha-helix, a decrease in beta-strand and fluorescence intensity of CPI. Surface hydrophobicity (H-o) of CPI significantly increased after HHP treatment, from 343.35 for native CPI to 906.22 at 600 MPa (P 0.05). HHP treatment at 200 MPa reduced zeta-potential and solubility of CPI, while had little effect at 400 and 600 MPa. Emulsifying activity and stability of CPI decreased after HHP treatment, of which droplet size of emulsions significantly increased (P 0.05). HHP-treated CPI could form heat-induced gelation at lower temperature (68.5 degrees C) and improved storage modulus (G ') comparing to native one (80.6 degrees C), suggesting that CPI might be potential protein resources as gelation substitute in food system.