Exploring different food-grade bigel systems for delivering bioactive carotenoids: Part 2 - Potential for extrusion-based 3D printing

The application of 3D printing technology in the food sector shows enormous potential for developing customized functional foods. Like this, novel materials are continuously being designed, allowing custom management of foods' composition, quantity, taste, color, structure, and texture in innovative shapes, offering novel product ideas to the food industry. The bigels appear as new ink for 3D-printed food models. They can potentially encapsulate bioactive components, protect, and release labile molecules in a complex matrix, and thus improve these foods' functional and nutritional properties. In this way, we develop different types of bigels, employing two hydrogels, varying H:O ratios, and concentrations of pitanga carotenoid extracts to obtain an ideal material for 3D foods printing with bioactivities and attractive color. Likewise, we seek to understand the effect of different proportions of bigels constituents on their structural and printability properties. The results were quite promising. All bigel formulations demonstrated good extrusion-based 3D printing capability, handling shear forces well and showing smooth, continuous extrusion. Print accuracy varied with bigel composition; Agar-based bigels (ABs) showed smaller dimensional deviations and better fidelity to designed models than gelatin-based bigels (GBs). Saponified carotenoid extracts resulted in higher hardness in ABs than non-saponified extracts, particularly noticeable at lower oleogel concentrations. GBs provided denser, mechanically stronger structures than ABs, influencing the texture and mechanical properties of 3D printed products. In conclusion, we highlight the impact of bigel composition, type of carotenoid extract, and H:O ratio on the printability and texture properties of 3D-printed bigels.