β-Cyclodextrin/resistant dextrin induced disparate gelling behaviors of high-protein liquid systems

High-protein, high-fiber foods are in the spotlight because of their health properties. Due to aggregation during heat treatment when dietary fiber is added, the amount of soy protein that can be used in the formulation of high-protein, high-fiber foods is limited. The effects of two types of soluble dietary fibers, β-cyclodextrin (β-CD) and resistant dextrin (RD), on the tunable thermal stability of soy proteins (SPs) and preheat-modified soy protein particles (SPPs), as well as the underlying mechanisms, were investigated. Results showed that β-CD (0.5-3.0 %, w/v) weakened the gels and introduced some degree of mobility, while RD (0.5-3.0 %, w/v) increased the gel strength and viscoelastic properties of SP and SPP gels. Dynamic light scattering analysis revealed that β-CD mitigated the increase in particle size of SPs and SPPs during heating, delaying gel formation at high protein concentrations. In contrast, RD promoted protein agglomeration into larger particles, speeding up the gelation process. Structural analysis revealed that β-CD preserved the integrity of protein structure, while RD promoted the unfolding of protein structure, leading to protein cross-links and aggregation formation. In summary, the effect of β-CD and RD on soy protein thermal stability provides valuable insights for developing new health-focused, high-protein, high-fiber products.