Omega-3 Incorporation Effects on Structural, Rheological, and Sensory Properties of 3D-Printed Chocolate

Abstract

Omega-3 fatty acids are highly valued for their health benefits but are challenging to incorporate into foods due to their instability and sensory drawbacks; challenges that 3D food printing can help address through precise material placement and structural design. This study investigates the combined effects of two forms of Omega-3 fortification, oil and microencapsulated powder, at varying concentrations (5%, 10%, 15%) on the physicochemical properties of 3D-printed chocolate. Particular emphasis is placed on formulations containing microencapsulated Omega-3, with further evaluation of their sensory attributes, storage stability, and potential to achieve both nutritional enhancement and product customization through 3D food printing, while maintaining structural integrity and masking undesirable flavors. The results showed that the form and addition level of omega-3 significantly affected the chocolate's crystallization behavior (ΔH increased from 44.30 ± 1.69 J/g in the control to 57.66 ± 2.02 J/g 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 properties (OP15 had the highest initial viscosity). Compared to oil, microencapsulated Omega-3 demonstrated superior compatibility with chocolate, including crystallisation and shape fidelity. Sensory analysis indicated that the OP10 formulation had comparable acceptability to the control when fresh, though its flavour acceptability declined significantly after two months of storage at room temperature (25℃). Overall, incorporating microencapsulated Omega-3 at a moderate concentration (5–10%) combined with optimised printing parameters, offers a promising strategy for enhancing the nutritional profile to meet recommended daily intake of Omega-3, structural fidelity, and consumer appeal of functional 3D-printed chocolate.