Exploring the potential of high hydrostatic pressure and ionic polysaccharides in improving interfacial stability of sweet potato protein hydrolysate emulsions

Summary This study aims to explore the potential of high hydrostatic pressure (HHP, 300–500 MPa) and ionic polysaccharides (sodium alginate, SA; chitosan, CH) in improving interfacial stability of sweet potato protein hydrolysate (SPPH) emulsions. HHP markedly improved emulsifying performance of SPPH with SA and CH at different concentrations (0.02% and 0.06%, w/v) and enhanced the apparent viscosities of their emulsions. SPPH‐CH0.02% at 400 MPa showed the highest emulsifying stability index (ESI, 255.96 min) and zeta potential absolute value (54.13 mV), and its emulsion exhibited the highest adsorbed peptide and CH at interface (31.72% and 1.51%, respectively) and oxygen radical absorbance capacity (ORAC) value of interfacial layer (264.56 μg TE mL −1 ). Additionally, multiple potential antioxidant peptides were obtained from interfacial layer of emulsion stabilised with SPPH‐CH0.02% at 400 MPa through LC‐MS/MS, and the relationship between their structure and emulsion stability was analysed. Therefore, HHP has great application potential in production of SPPH‐CH emulsion with enhanced stability.