Abstract:
This study aimed to investigate the effects of different concentrations (0, 0.06, 0.08, 0.10, 0.12, 0.14, 0.16 g/mL) of corn starch (CS) on the 3D printing accuracy of tremella polysaccharide-egg white protein (TFP-EWP) composite gels, as well as the influence of varying microwave vacuum freeze-drying times (0, 20, 40, 60, 80, 100, 120 min and 140 min) on the solidification properties of the printed products. TFP-EWP-CS gels with different CS concentrations were used as the raw material, and the printing accuracy of the products was characterized. Microwave vacuum freeze-drying was applied as the drying method, and the products were systematically evaluated for moisture content, drying rate, geometric shape, texture, color difference, and moisture distribution. The results indicated that at a CS concentration of 0.12 g/mL, the 3D printing deviation of the TFP-EWP-CS composite gel was the lowest, with a deviation value of 0.75%. As the drying time increased, the proportion of free water significantly decreased, while some weakly bound water converted to free water and subsequently evaporated, leading to a decline in both moisture content and drying rate. During the processing times of 20, 40, 60, and 80 min, the shape of the printed products remained relatively stable, with a solidification fidelity greater than 90%; however, both the diameter and height significantly decreased (
P<0.05). Surface cracking was observed at 100 min of drying. As drying time increased, the hardness, adhesiveness, and chewiness of the products significantly enhanced, while the microwave vacuum freeze-drying treatment increased the whiteness and reduced the yellowness of the products (
P<0.05). In conclusion, this study provides valuable references for optimizing the drying process of TFP-EWP-CS composite gel printing products.