Omega-3 incorporation effects on the structural, rheological, and sensory properties of 3D-printed chocolate

Abstract

Omega-3 fatty acids are recognised for their health benefits but their incorporation into foods is limited by oxidative instability and undesirable sensory attributes. 3D food printing offers a potential solution by enabling precise spatial deposition and structural design to improve stability and product quality. This study examined the effects of two fortification forms, free oil and microencapsulated powder, at three concentrations (5%, 10%, 15%), on the physicochemical characteristics of 3D-printed dark chocolate. Particular emphasis was placed on microencapsulated formulations, with additional evaluation of sensory properties, storage stability, and their capacity to achieve nutritional enhancement while maintaining product integrity and acceptability.Results demonstrated that both form and concentration of omega-3 significantly influenced crystallisation behaviour (ΔH increased from 44.30 ± 1.69 J g⁻¹ in the control to 57.66 ± 2.02 J g⁻¹ in OP15, p < 0.05), texture (breaking force decreased from 84.46 ± 3.99 N in the control to 48.14 ± 4.14 N in OP15 and 25.86 ± 5.14 N in OO15), and rheological behaviour (OP15 exhibited the highest initial viscosity). Compared with oil, microencapsulated omega-3 showed superior compatibility with the chocolate matrix, enhancing crystallisation and shape fidelity. Sensory analysis revealed that OP10 achieved comparable overall acceptability to the control when fresh, although flavour scores decreased significantly after two months of storage at 25 °C. Overall, fortification of omega-3 at moderate levels (5–10%), combined with optimised printing conditions, provides an effective strategy to improve nutritional value, structural performance, and consumer acceptance of functional 3D-printed chocolate.