Edible 3D printed emulsion gels: Effects of inulin on sensory characteristics and mechanical properties

Inulin is a prebiotic and an effective texture modifier for emulsion gels, offering considerable commercial value for consumers whose chewing ability changes. This study evaluated the influence of inulin on print precision, structural integrity, and sensory quality of 3D-printed emulsion gels. An inulin-based emulsion gel with desirable texture and freezing stability across -18 °C to 25 °C was successfully developed. Rheological analysis showed a pronounced increase in elasticity with increasing inulin content. In frequency scanning, G' rose from 2.99 × 10³ Pa (6.7 % inulin) to 1.08 × 10⁴ Pa (20 % inulin), while oscillation scanning showed a rise from 2.27 × 10³ Pa to 7.18 × 10³ Pa. Frequency and thixotropy tests revealed that salt-free gels exhibited the highest G' and viscosity. Temperature scanning showed peak moduli at -18 °C (G' = 2.44 × 10⁶ Pa; G″ = 1.09 × 10⁶ Pa). Notably, G' in 20 % inulin gels declined only 65 % after thawing, compared to 76 % in 6.7 % gels, confirming better freeze-thaw stability. Electronic-nose detection and sensory evaluation indicated that higher inulin levels diminished the characteristic camellia-oil odor. Correlation analysis demonstrated that hardness was inversely related to fatty and smooth sensory attributes, highlighting the predictive value of instrumental measurements for sensory texture in 3D-printed foods.