Effect of geometry on curcuminoid retention in 3D-printed turmeric powder-enriched crackers

This study evaluated the enrichment of 3D-printed crackers with turmeric rhizome powder in different geometries, focusing on how geometry affects the retention of turmeric’s bioactive compounds and the appearance of crackers during storage. The cracker doughs were prepared using dry turmeric powders at concentrations of 0, 1, 2, and 3% (w/w). The doughs were 3D-printed using different geometries (cylinder, hollow cylinder, triangular prism, cube, and racetrack). Rheological properties, printability, color, texture, and microstructure of the samples were analyzed. Doughs with 2% turmeric showed the best printability and shape stability after baking and storage, while the control (0%) and 3% turmeric samples showed the lowest stability after storage. So, crackers formulated with 2% turmeric were selected for further evaluation of curcuminoid stability. Viscosity measurements confirmed that all doughs exhibited shear-thinning behavior. Increasing turmeric concentration resulted in darker-colored crackers with more yellow and red tones. The hardness of the printed crackers varied based on geometry and turmeric content. Geometry and storage conditions influenced curcuminoid retention, with the hollow cylinder geometry showing suitable stability, as no significant differences in curcuminoid contents were observed between day 1 and day 30. Baking reduced curcuminoid content by more than 40%, while the triangle, hollow cylinder, and racetrack geometries showed the highest retention rate after 30 days of storage (>86%). This study demonstrates the potential of 3D printing to produce curcuminoid-enriched crackers and highlights the impact of geometry on the stability of bioactive compounds during storage.