Effect of hybrid gelator systems of beeswax-carrageenan-xanthan on rheological properties and printability of litchi inks for 3D food printing

Abstract

Hybrid gelators can be used for improving textural and rheological properties of foods, have more potential for 3D printing. This paper studied the rheological, microstructural and 3D printing characteristics of litchi pulp with hybrid gelators of beeswax, κ-carrageenan and xanthan gum. The rheological results showed that, in the extrusion stage of 3D printing process, the yield stress of the hybrid gelator ink (HGI) was 623.27 ± 4.38 Pa, the K and n value were 2.92 × 105 Pa·sn and 0.12 ± 0.01, respectively. In recovery stage, the time of shear viscosity returned to a stable was 30 s and the gelation time was 124.52 s for HGI. In self-supporting stage, the G′ of HGI was almost 10 times that of hydrogelator ink (HI). These results indicate that HGI has good shear-thinning, recovery and mechanical properties. Differential scanning calorimeter and X-ray diffractometer revealed that this rheological property was caused by the beeswax in the hybrid gelators after incubation (45 °C) that produced more orthorhombic structure and consumed the energy in the ink. The microstructure indicated that the HGI was a hybrid gelator systems filled with beeswax, which increased the printability of the material during the printing process. The product printed with HGI has high precision, and could withstand an inclination angle of 53.5° and a layer height of 85 layers. These hybrid gelator systems play a guiding role in improving the stability, precision and formability of 3D printed products.