Speaker
Description
Extrusion-based 3D food printing enables highly accurate spatial control, but its wider deployment remains constrained by the absence of robust and transferable material parameters for printability. Consequently, commercial systems often rely on proprietary inks, while academic studies frequently report formulation-specific processing windows, thereby counteracting personalization. In plant-based edible inks, inadequate correlation between protein attributes and techno-functionality, together with an incomplete understanding of process-structure interactions, further compounds this challenge.
X-ray scattering (XRS) provides a non-destructive route to characterize hierarchical and multiscale structure in complex food systems, enabling probing for features potentially relevant to printing performance. Herewith, four soy-based formulations prepared from two techno-functionally distinct soy protein isolates (SPI) under distinct pre-processing routes (direct kneading or high-shear-homogenization), were investigated using benchtop XRS with wide-angle X-ray scattering (WAXS) and small-angle X-ray scattering (SAXS), including measurements of individual dry ingredients, hydrated components and thermal treatment.
Scattering patterns differed between shortly hydrated and overnight-hydrated inks, highlighting the utility of benchtop access for tracking structural evolution due to processing steps dependence. WAXS distinguished differences in secondary protein fractions of differing purity. SAXS revealed the emergence of a distinct low-q feature (q = 0.01–0.08 Å⁻¹) upon heating of pure SPI. Similar signatures have been linked to protein nano-aggregate formation in structured plant-protein matrices and in the present study, a related low-q shoulder was also observed in the pre-processed formulated inks but not in the individual ingredients. These structural observations were distinct across the four formulations yet showed consistent trends alongside microstructural features visualized by confocal laser scanning microscopy and mechanically characterized by rheology-derived gel strength, suggesting that ingredient selection, including SPI type and pre-processing route, influences protein aggregate formation and ultimately printability.
Overall, benchtop XRS demonstrated its capability as an effective screening tool for multiscale structural characterization of multi-component edible inks, providing a structure-informed basis for future work on how protein aggregation characteristics may govern processing performance in plant-based 3D food printing.