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In the present study, the synergetic gelation of curdlan gum (CG) and gellan gum (CG) at different biopolymer ratios were investigated. The optimal gelation of CG and GG was determined at total biopolymer concentration of 0.6% and a mass ratio of 1:1 according to visual observation and viscoelastic properties. The gelation behavior of the CG/GG binary composite gel exhibited ratio-dependent behavior at different biopolymer mixing ratios (2:8–8:2). With the increase in the CG/GG ratio from 2:8 to 8:2, the gel strength and transition temperature of the CG/GG gel showed an increasing trend followed by a decrease, reaching a peak at 5:5, with corresponding G′ , melting and gelling temperatures of 335.8 Pa, 82.5 °C and 33.7 °C, respectively. The improved gel properties could be ascribed to hydrogen bonds between CG and GG, as reflected by the blueshift of the O–H vibration peaks and water associated regional variation. Moreover, the CG/GG binary composite gel exhibited a significantly increasing water holding capacity (WHC) as the ratio of CG/GG decreased from 8:2 to 4:6, while the excess involvement of GG had no effect on the WHC improvement. Furthermore, the CG/GG binary composite gel exhibited denser and more homogeneous microstructures in comparison to individual CG and GG and performed the most compact gel network at ratio of 5:5, supporting the stronger gel rigidity and WHC. Therefore, these novel CG/GG hydrogels showed considerable gel strength and microstructures, which would provide a better mechanistic understanding of the polysaccharide complex in practical applications as a hydrogel base material. [Display omitted] • The addition ratio between CG and GG exhibited a significant effect on the synergy. • CG/GG binary composite gels exhibited good water holding capacity. • The CG/GG binary composite gels mainly driven by hydrogen bonding forces. • The CG/GG binary composite gels exhibited dense and homogeneous microstructures. [ABSTRACT FROM AUTHOR]

To develop composite hydrogels based on low acyl gellan gum (GG), the effect of puerarin (PUE) on the gel properties of GG was investigated. The results showed that the maximum storage modulus (G ′) of the 1.2 % GG/0.8 % PUE composite hydrogel was 377.4 Pa at 0.1 Hz, which was enhanced by 4.7-fold compared with that of 1.2 % GG. The melting temperature of this composite hydrogel increased from 74.1 °C to >80.0 °C. LF-NMR results showed that a significant amount of free water was present in the hydrogel matrix. The surface structure aggregation and the shrinkage of the honeycomb meshes in the composite hydrogel proved the cross-linking of PUE and GG. XRD, FTIR and molecular simulation results illustrated that hydrogen bonds were the most important factor controlling the interaction between GG and PUE. Thus, the GG/PUE composite hydrogel has good elasticity, thermal stability and water retention, which lays a good foundation for further application in the food industry. [ABSTRACT FROM AUTHOR]