Improvement of ultrasound microwave-assisted enzymatic production and high hydrostatic pressure on emulsifying, rheological and interfacial characteristics of sweet potato protein hydrolysates

Herein, we investigated effects of ultrasound microwave (UM)-assisted enzymatic hydrolysis and high hydrostatic pressure (HHP, 300, 400 and 500 MPa) on emulsifying, rheological and interfacial characteristics of sweet potato protein hydrolysates (SPPH). UM significantly improved emulsifying properties of SPPH. Emulsion stabilized with SPPH by UM at 400 MPa was the most physically stable with ESI of 43.16% compared with other emulsions, which showed lower particle size (239.25 nm) but higher zeta potential (26.75 mV). HHP increased adsorption and antioxidant activity of SPPH at interfacial layer. Emulsion stabilized with UM-SPPH400MPa presented the highest adsorbed peptides at interface (23.79%) with a high ORAC value of 100.49 μg TE mL−1, from which diverse peptides with potential antioxidant activities were obtained by LC-MS/MS. Additionally, changes in peptide conformation and position of some specific amino acids were revealed by structure-activity relationship analysis. Therefore, ultrasound-microwave and HHP have great potential in peptides production with enhanced functionality.