Balancing lubrication and structural integrity in 3D-printed plant-based meat analogues through partial oil substitution with aloe gel and flaxseed mucilage

Three-dimensional (3D) printing offers a versatile route to plant-based meat analogues, enabling precise fabrication of fibrous structure while minimising material waste and energy consumption. However, a key challenge in this approach is formulating printing inks that balance extrudability with structural integrity during and after printing. This study investigates the potential of aloe gel and flaxseed mucilage as fat replacers in 3D-printable meat analogue pastes, evaluating their effects on printability, particle size distribution, rheological and tribological properties, as well as the texture and water retention capacity of the cooked products. The oil-lubricated sample showed high stiffness and poor particle dispersion due to oil-induced protein aggregation, which interfered with extrusion flow and compromised printing precision. In contrast, formulations with full-fat replacers demonstrated improved flowability, characterised by lower yield stress and storage modulus, enabling smooth extrusion and accurate filament deposition. However, these improvements come at the cost of lubrication performance, highlighting the essential role of oil in achieving effective tribological properties. Formulations with partial oil replacement successfully balanced rheological and tribological behaviour, offering enhanced printability while maintaining lubrication performance comparable to the fully oil-lubricated formulation. Furthermore, the partially substituted samples retained key quality attributes, including post-cooking texture and water retention capacity. Overall, aloe gel and flaxseed mucilage show promise as functional fat replacers for low-fat 3D-printed meat analogues, enabling healthier formulations. These findings support their application in clean-label, reduced-fat product development, contributing to ongoing innovation in the plant-based meat sector. • Aloe gel and flaxseed mucilage used as fat replacers in 3D-printed meat analogues. • Partial oil replacement balanced rheology and tribology, enhancing printability. • Substituted samples retained texture and water retention capacity after cooking. • Findings support healthier, clean-label, reduced-fat plant-based meat formulations.