Fabrication, characterization, and performance of microalgae-hydrocolloid stabilized inks for 3D printing applications

Three-dimensional (3D) printing is increasingly transforming various manufacturing sectors by enabling the production of customized and sustainable products. Achieving reliable pre- and post-printing performance requires rigorous assessment of ink printability, particularly in systems with complex structural hierarchies. In this study, three ink systems - Guar gum (GGu), Gum Acacia (GAc), and Pectin (PEc), incorporating the novel microalga Desmodesmus abundans (GenBank accession number: PP905124) were developed and evaluated for 3D printing. Molecular identification via 18S rRNA sequencing confirmed the isolated strain, which exhibited a balanced biochemical profile. Ultra High-Performance Liquid Chromatography (UHPLC) analysis quantified 81.42 mg/100 g of essential amino acids, with methionine as the dominant component, and 124.50 mg/100 g of non-essential amino acids, with asparagine predominating. Rheological analysis demonstrated that the 1 % GGu ink offered superior printability, characterized by optimal viscosity (14.94 ± 0.48 Pa.s) and a predominantly elastic behaviour (G′ > G″), resulting in smooth extrusion and stable constructs. In comparison, GAc and PEc-based inks exhibited viscous-dominant behaviour with limited structural stability. Control experiments demonstrated the critical role of microalgae, hydrocolloids, and calcium chloride-mediated cross-linking in preserving post-printing integrity. FTIR, SEM and TPA analysis further confirmed stronger hydrogen bonding and ionic crosslinking in GGu compared to the other inks. Collectively, these results provide a framework for functional 3D ink design and emphasize the potential of 1 % GGu combined with D. abundans as a sustainable, nutrient-rich ingredient for future personalized food fabrication. © 2026 Elsevier B.V.