The formation of rice starch/casein complex by hydrothermal and stabilizing high internal phase emulsions with 3D printing property

Abstract

The high internal phase emulsions (HIPEs) are suitable for 3D printing because of their good self-supporting and shear-thinning. However, the HIPEs prepared from single unmodified casein showed bad self-supporting and could not be used for 3D printing. Therefore, the rice starch/casein complex (SC) was prepared and used in the HIPEs for 3D printing. The SC was treated at different hydrothermal temperatures (60, 80, and 100 °C), and FTIR, XRD, and DSC confirmed the formation of SC by hydrogen bonds. The DSC, apparent viscosity, and microstructure revealed the degree of gelatinization of SC, which affected the properties of the HIPEs. When the degree of gelatinization of SC increased from 12.35% to 70.62%, the HIPEs prepared from the SC treated at 100 °C for 1 h had higher storage modulus, viscosity, and three-interval thixotropy, including lower frequency dependence, which showed the desirable 3D-printing qualities, that is, easy extrusion, stable recovery, and self-supporting. The storage stability of HIPEs prepared from SC showed stable storage at low temperatures (4 °C > 25 °C). These results suggest that rice starch/casein with a higher degree of gelatinization could be used to prepare HIPEs with good 3D-printing characteristics. Furthermore, the developed HIPEs could be applied for 3D printing of foods with the personalized shape.