Comparative Analysis of Structural Characterisation and Gel Properties of Blended/Co-Precipitated Soy-Pea Dual-Protein

This study proposed a pH-driven co-precipitation strategy to overcome the limitations of traditional physical blending in functional improvement of a dual-protein system. The results demonstrated that, in comparison with the soy-pea blended protein (SPBP), the soy-pea co-precipitated protein (SPCP) showed a decrease in α-helix and β-sheet content, accompanied by in an increase in random coil structure. SPCP exhibited decreased fluorescence intensity, smaller particle size (from 392.2 to 176.1 nm) with increased absolute zeta-potential values (from -13.7 to -19.7 mV), reduced surface hydrophobicity (from 21,987.3 to 9744.8), and increased content of disulfide bonds. Structural optimization of SPCP significantly bolstered intermolecular interactions between SPI and PPI. Molecular docking simulations also validated the presence of abundant hydrophobic interactions and hydrogen bonds within in the blend system. These modifications significantly enhanced the solubility of SPCP (especially SPCP8.0). The rheological analysis further revealed that the storage modulus (G') and loss modulus (G″) of SPCP8.0 were both higher than those of SPBP, while its tan δ was lower than that of SPBP, indicating synergistic interactions between proteins. These interactions contributed to the formation of a more stable three-dimensional network structure, thereby conferring it with superior gel properties. These findings provide theoretical foundations for improving the functional properties of plant-based dual-protein and their applications in plant-based meat production.