Modulating physicochemical properties of 3D printed gelatin-ethyl cellulose bigel by oleogel/hydrogel ratios and...

Ethyl cellulose-gelatin bigels were developed and impacts of different hydrogel/oleogel ratios and emulsifiers (PGPR, monoglycerides, diglycerides, and lecithin) on their physicochemical properties were revealed for the first time. Monoglycerides disrupted oil structuring of ethyl cellulose. PGPR and lecithin strengthened elastic properties of oleogels. Bicontinuous structure appeared in bigels with lecithin when decreasing oleogel fraction from 70 % to 30 %. While other bigels showed transition of W/O to O/W structure. These bigels had gel-like structure with temperature depending G' and G″. Bigels containing monoglycerides and lecithin showed a step-like sol-gel transition. Hardness of bigels grew with decline of oleogel content due to high hardness of the hydrogel. Hydrogel/oleogel ratios and emulsifiers modulated hydrogen proton distribution and thermal properties of bigels. Bigels with three emulsifiers exhibited good printability at 70 % and 50 % oleogel content owing to suitable mechanical properties. This work provides a new insight into modulating properties of ethyl cellulose-gelatin bigels.