Improving the solubility and interfacial absorption of hempseed protein via a novel high pressure homogenization-assisted pH-shift strategy

[Display omitted] •HPH-assisted pH shift treatment markedly increased the solubility of hemp protein.•Enhanced structural unfolding in pH shifted hemp protein was spotted when pressurized.•The particle size of hemp protein was reduced by the combined treatment.•Changes in protein structure impelled the absorption of proteins at the oil–water interface. A pH shift treatment aided by high pressure homogenization (HPH) with various pressures (0–120 MPa) was employed to structurally modify hempseed protein isolate (HPI). Compared with individual pH shift or HPH treatment, HPH-assisted pH shift improved the structural flexibility of HPI, as revealed by the increased random coil in protein secondary structure. With the incorporation of HPH into pH shift, the intrinsic fluorescence intensity was remarkably attenuated and redshifted, whereas the surface hydrophobicity was pronouncedly boosted, indicating the extensive unfolding of protein structure. Moreover, the cotreated HPI exhibited a smaller and more homogenous particle size, notably at a higher pressure. Consequently, the solubility was drastically raised by the cooperated treatments, to the maximum value (62.8 %) at 120 MPa. These physicochemical changes in the cotreated HPI facilitated a consolidated interfacial activity. Moreover, the cooperated treatment, especially highly pressured (120 MPa), facilitated the penetration and rearrangement of proteins at the oil–water interface.