3D printing characteristics of wheat starch

Wheat starch was extracted from high-gluten wheat flour, medium-gluten wheat flour and low-gluten wheat flour, respectively, to determine the most suitable wheat starch type for 3D printing. The relationship between the physical and chemical properties of wheat starch and 3D printing characteristics was discussed by measuring the chromaticity, pasting properties, particle size distribution, hydration properties, light transmittance, retrogradation, water holding capacity, oil holding capacity, 3D printing characteristics, rheological properties and amylose content and density of wheat starch after pasting and printing. The results showed that wheat starch extracted from wheat flour with different gluten content had a significant effect on 3D printing characteristics. The wheat starch (wheat starch 2, ZS) extracted from wheat flour with gluten content of 25.3% had the best printing effect, which showed obvious printing lines, and the printing lines did not break. The size of the printing lines was close to that of the CAD target model. The gelatinization temperature and gelatinization time of the three wheat starches decreased in turn, and the attenuation value and retrogradation value of ZS were moderate, indicating that the thermal stability and hardness of ZS were moderate. The particle size distribution results showed that the ZS distribution span was smaller and the particle dispersion was more uniform. The light transmittance of the three starches showed a trend of increasing first and then decreasing. After 3D printing, the amylose content of the three starches increased and the density decreased. In addition, the loss modulus (G') had an effect on its extrusion behavior, the storage modulus (G″) affected the support ability of the 3D printed sample, and the loss tangent (tan δ) contributed to the starch extrusion molding. Rheological results showed that wheat starch 2 had the largest G' and G″, and tan δ was at a medium level, which was easier to be extruded from the nozzle, and could also maintain rapid recovery and solidification of the structure after extrusion. Therefore, wheat starch 2 is more suitable as a starch-based 3D printing material, which is suitable for wheat starch in 3D printed food.