Correlating rheology with 3D printing performance based on thermo-responsive κ-carrageenan/Pleurotus ostreatus protein with regard to interaction mechanism

Accurate 3D printing of thermo-responsive gel inks is a great challenge as the sol-gel transition and rheological properties change during extrusion are not easy to precisely regulate with 3D printing behavior has not been sufficiently studied. The effect of Pleurotus ostreatus protein (POP) correlated with the rheological properties and thermo-responsive behavior of the system on 3D printing performance of the thermo-responsive gel, namely κ-carrageenan (KG). Afterwards, their interaction mechanism was further clarified and final printed samples were evaluated in terms of antioxidant performance. Results indicated that POP addition increased the gelatinization temperature (Tg), significantly affecting the selection of optimum printing temperature. POP addition also improved viscosity and consistency index (K) of the printing ink, ultimately affecting the extrusion behavior. Temperature recovery property was facilitated by POP incorporation and was critical to the formability during recovery stage in 3D printing. Mechanical strength was improved with POP addition, which played an important role for the printed structures to be self-supportive. A lower concentration of POP (10%∼40%) was dispersed in a continuous KG-rich gel network and visible phase separation occurred when POP level was increased to 50%. Molecular interaction analysis showed that electrostatic interactions, hydrophobic interactions, ion on the correlation between the rheological properties and thermo-responsive behavior of gum-based 3D printing ink. In addition, POP presented a certain antioxidant activity. This study not only provided useful information on the correlation between the rheological and thermo-responsive behavior of gum-based 3D printing ink, but also provided a way to regulate 3D printing behavior of gum-based gel by protein incorporation. Moreover, it also showed the way to improve the nutritional value of the 3D printed sample.