Effect of sodium chloride solution on quality of 3D-printed samples molded using wheat starch gel

This study presents a new method of 3D printing food constructs using wheat starch gel, with a NaCl (sodium chloride) addition, and investigates the influence of the NaCl addition on the gel and final product. The results showed that when the NaCl concentration in wheat starch was 150 mmol/L (mM), the support stability, line uniformity and height retention of printed samples all achieved an appropriate optimization. Highly concentrated NaCl helps the gel to flow from the nozzle quickly, yet still allows the gel to be viscous enough post deposit so that it can hold its good-resolution shape. Samples that were printed with starch gel containing the 150 mM NaCl maintained a soft and elastic texture, even after long-time storage. This may be attributed to the hindrance of the polymerization between starch molecules and the inhibition of crystal growth that occurs when Na+ enters starch molecules. NaCl thereby inhibits the retrogradation of starch and enhances its stability.