The Characteristics and Mechanism of Curdlan Gum Replacing Sucrose to Enhance the Gelation of High-Methoxy Pectin and Its Improvement Effect on Gummy Candy

To address the poor thermal stability and excessive reliance on sucrose of high-methoxy citrus pectin (HM-CP) hydrogels, this study investigated the characteristics and mechanism of curdlan gum (CG) as a sucrose substitute in binary hydrogels with various HM-CP/CG ratios. Results demonstrated that increasing the CG proportion significantly enhanced the rheological properties, hardness, gumminess, chewiness, thermal stability, and water-holding capacity of the hydrogels at a concentration of 7%. Among the tested proportions, the optimal 7% HM-CP/CG-2:8 binary hydrogel had the highest gelation temperature at 62.46 °C and the highest hardness at 245.11 g. Moreover, the hydrogel exhibited optimal gel properties, with the dense and uniform three-dimensional network structure primarily attributed to intermolecular hydrogen bonding. Application tests confirmed that the optimal binary hydrogel can be successfully used to produce gummy candies with improved textural and sensory characteristics, providing a theoretical basis for the application of HM-CP and CG in food products.