Blueberry leaf polysaccharide/gelatin composite gel: Preparation, characterization, and formation mechanism

This study investigates the effects of isolated blueberry leaf polysaccharides at varying concentrations on the gel behavior of gelatin composites. The formation of stable blueberry leaf polysaccharide-gelatin gels was attributed to hydrogen bonding, electrostatic interactions, and hydrophobic interactions. SEM revealed that the composite gels exhibited a more compact and uniform structure. TPA results indicated that the incorporation of blueberry leaf polysaccharides significantly enhanced the hardness, viscoelasticity, and chewiness of gelatin. Notably, as the concentration of blueberry leaf polysaccharides increased from 0 % to 2.5 %, the thermal stability of the composite gels improved correspondingly. Rheological analysis demonstrated that the storage modulus (G') consistently exceeded the loss modulus (G") across the entire frequency range, indicating that the composite gels exhibited viscoelastic solid behavior. Furthermore, temperature scanning indicated that the melting temperature (T_m) of the composite gels was slightly elevated compared to that of pure gelatin. These findings contribute to the development of novel gelatin composite products, promote the comprehensive utilization of blueberry leaf polysaccharides, and expand the application of gelatin in complex food systems.