Valorization of agar production residue as a filler in soy protein hydrogels for 3D printing

Abstract

Cellulose-containing residue from agar production was incorporated as a filler into soy protein-based hydrogels and revalorized without further purification. Rheological assessment of these hydrogels was carried out in order to confirm their shear-thinning behavior and their suitability for 3D printing. It was observed that all hydrogels behaved as weak gels, which are suitable for 3D printing and have good printability and shape fidelity. The addition of cellulose did not cause chemical crosslinking but physical interactions, which led to morphological changes, thereby promoting hardness and shape recovery of the 3D-printed products. The hydrogel with the highest residue content (8 wt %) showed the highest value (78%) in shape recovery. Furthermore, the physicochemical characterization of these 3D-printed products revealed that although they have high swelling capacity, they preserve their integrity in wet conditions. These results suggested the potential of the 3D-printed products developed using residues without further purification to promote circular economy, increasing the efficiency in resources utilization.

Binary Pea Protein–Psyllium Hydrogel: Insights into the Influence of pH and Ionic Strength on the Physical Stability and Mechanical Characteristics

“…The hydrogels’ LVR (linear viscoelastic region) occurs at low shear stress when the moduli are independent of increasing stress (the system’s response is independent of the deformation magnitude, and the structure is maintained intact). Because structural properties correlate well with elasticity, the length and value of the LVR of the elastic modulus (G’) can be used to assess sample structure stability [ 60 , 61 ]. The values of LVR determined in this study are presented in Table 4 .…”