Effects of high hydrostatic pressure on emulsifying properties of sweet potato protein in model protein–hydrocolloids system

The effects of high hydrostatic pressure (HHP) on emulsifying properties of sweet potato protein (SPP) in presence of 0.1%, 0.3% and 0.5% (w/v) of guar gum (GG) and glycerol monostearate (GMS) were investigated. Emulsifying stability index (ESI) of the SPP with GG revealed significant increase (P < 0.05) in ESI value at 600 MPa treatment, while the stability of SPP–GMS emulsions significantly decreased with increase in GMS concentrations and HHP treatments (200–600 MPa). HHP treatment considerably reduced the creaming rate for SPP–GG model while such case was not observed for SPP–GMS model. The flow index for SPP–GG emulsion model was found to decrease with increase in HHP treatment and had non-Newtonian behaviour. The SPP–GMS emulsion models with HHP treatments showed comparatively lower viscosities but had more Newtonian flow character.