Accelerated gelation and strengthened network formation in whey-pea binary protein systems via linear or branched β-glucans

Developing sustainable plant-animal binary protein gels is limited by weakened gel properties arising from the partial replacement of animal proteins with plant proteins. Although β-glucan could effectively promote aggregation and gelation in single-protein systems, its functionality in binary protein systems remains largely unexplored. Herein, oat β-glucan (OG) and yeast β-glucan (YG), differing in structural characteristics, were incorporated to construct a robust interacting whey-pea protein system with strengthened gelling properties. Conformational and interaction analyses revealed that β-glucan induced the formation of larger aggregates by unfolding protein structure, enhancing hydrophobic interactions, and reducing electrostatic repulsion. With relevance to the enhanced cross-linking, β-glucan triggered a phase transition of the binary protein system from liquid to gel state upon heating. The resulting robust gel network markedly restricted the diffusion of non-network proteins and reduced the mobility of the remaining immobilized water. Notably, YG exhibited a greater capacity than OG to enhance gel stiffness and network density, likely due to stronger hydrogen-bonding interactions conferred by its branched structure. Furthermore, YG accelerated gelation by shortening the nucleation period through increasing the concentration of unfolded proteins. This study provides new insights into leveraging β-glucan structure to enhance the gelation and functionality of sustainable plant-animal binary protein systems.