Functional and structural modulation of oat milk–based vegan chocolate by lemon microcapsules

The growing demand for vegan and functional foods has increased interest in improving the nutritional quality of plant-based confectionery. This study investigated the effects of partial sucrose replacement (0–10 g/hg) with maltodextrin-encapsulated lemon extract on the physicochemical, structural, functional, and sensory properties of oat milk–based vegan milk chocolate. Increasing microcapsule levels significantly reduced pH (5.12–4.21) while increasing total phenolic content (70.40–94.55 μg GAE/g), vitamin C content (77.58–157.89 mg/hg), and antioxidant activity, as indicated by decreased IC 50 values (2.75–2.24 mg/mL). Moderate substitution resulted in slight darkening and controlled softening without affecting particle-size distribution or the dominant β 2 (Form V) cocoa butter polymorph. Sensory evaluation identified 2.5 g/hg substitution as the optimal formulation, providing enhanced antioxidant properties with acceptable flavor, color, and texture. Higher substitution levels (5–7.5 g/hg) further increased bioactive content but introduced mild acidity and bitterness, whereas 10 g/hg offered limited additional functional benefits and reduced sensory acceptability. Controlled sucrose replacement with maltodextrin-based lemon microcapsules is a technologically feasible approach for developing functional oat milk–based vegan milk chocolate, allowing tunable functional enhancement while preserving processing feasibility, structural integrity, and cocoa butter polymorphic stability. • Encapsulated lemon extract enabled sugar reduction in vegan chocolate. • Antioxidant activity increased without altering cocoa butter polymorphism. • The stable β 2 (Form V) structure was maintained in all formulations. • A 2.5 g/hg substitution balanced functionality and sensory acceptance. • Higher levels enhanced functionality with preserved structural stability.