Effects of sodium chloride on the textural attributes, rheological properties, microstructure, and 3D printing performance of rice starch-curdlan composite gel

This study explores the impact of varying concentrations of salt ions (0, 2.5, 5, 7.5, 10, and 12.5 mmol) on the physicochemical properties and 3D-printing performance of rice starch-curdlan composite gel. The relationship between gel structure, properties, printability, and printing accuracy was clarified through the evaluation of each parameter. The inclusion of an appropriate concentration of NaCl positively influenced the properties and printing characteristics of the composite gel. Specifically, a NaCl concentration of 7.5 mmol yielded the highest printing performance, achieving 98.61 % accuracy. Microstructural analysis indicates that the addition of ions promoted the formation of a denser network structure in the composite gel. Fourier-transform infrared spectroscopy reveals enhanced hydrogen bonding in the rice starch-curdlan gels with the addition of NaCl. Lastly, dysphagia testing demonstrates that the composite gels with 0–5 mmol NaCl concentrations exhibited grade 5 characteristics (clastic and wet) with satisfactory swallowing performance.