Impact of different natural sweeteners on 3D printability and post-printing quality of marzipan

Food 3D printing technology presents an avenue for enhanced product customization and functionality. Focusing on the impact of sweeteners, in this study, marzipan, a traditional almond-based confectionery, was 3D printed with four different natural sweetener variants (table sugar (TS), stevia (SS), monk fruit (MF) and yacon root powder (YR)). The effects on rheological behavior, 3D extrusion printability, post-printing stability, and sensory quality attributes were investigated. To assess material printability, steady-state, oscillatory, and 3ITT rheological tests were performed. Results indicated that all formulations exhibited favorable printability characteristics, with higher storage moduli than loss moduli, explaining the elastic solid-like behavior essential for extrusion 3D printing. Thixotropic testing revealed time-dependent recovery behavior in all formulations (recovery percentage range = 63.2 - 70.5 %). Further, X-ray diffraction studies confirmed the crystalline nature (degree of crystallinity range = 38 - 58 %) of all formulations. All material supplies were categorized as low glycemic index products (GI = 45.06–53.33). Printing conditions to print a 3D chalice model were optimized at a nozzle size of 1.22 mm, motor speed of 15 rpm, compressed air pressure of 3 bar, and printing speed of 800 mm/min. Stability assessment of printed constructs at varying infill densities (25, 50, and 75 %) and time intervals (6, 12, 18, 36 h), alongside sensory evaluation, highlighted that the TS formulation was best, followed by MF. These findings hold significance for the development of customized 3D printed products in which GI is a critical consideration and in cases where natural sugar alternatives are considered.