Fabrication and Characterization of novel high internal phase bigels with high mechanical properties: Phase inversion and personalized edible 3D food printing

Abstract

In this paper, bigels systems were prepared by using 20 wt% palm stearin (POs) structured soybean oil oleogels and 80 wt% xanthan gum hydrogels in different ratios of polyglycerol polyricinoleate (PGPR). The proportion of PGPR in bigels was changed to explore the phase inversion and stabilization mechanism of bigels by multiple microscopy techniques, and the mechanical properties have been evaluated by the rheology analysis and 3D printability. When the PGPR content was less than 0.4 wt%, bigels presented as the O/W type. As the PGPR content was 1.0 wt% and 1.2 wt%, the bigel presented as the W/O type with a high internal phase, and a high level of droplets dispersed closely within an oil phase. The increase in PGPR content slowed down the nonlinear viscoelastic behavior under large strains. In terms of 3D printing capability, bigels (oleogels containing 20 wt% POs) showed an unsatisfactory 3D printing capability. However, with the increase of POs and PGPR content, more plastic and printable W/O high internal phase bigels were obtained due to the formation of a more stable, homogeneous, and strong ink. In addition, the bigels systems were investigated for the preparation of 3D biscuit printing, and it was found that the K′ value of W/O bigels batter (1511.39) was larger than that of O/W bigels batter (1394.82), showing greater hardness and better 3D printing performance. These findings could facilitate the broadening of bigels systems that could be applied for 3D biscuit printing.