Valorization of saffron petal and vitamin D3 nanoemulsion in functional milk powder: Influence of drying techniques on physicochemical and sensory quality

• Functional milk powder (FMP) was produced by basil seed -based nanoemulsion. • This nanoemulsion was formulated by saffron petals, and vitamin D3. • Spray (CSD), freeze (FD), and Refractance Window drying (RWD), were employed to generate the FMP. • FMP-FD demonstrated the highest antioxidant capacity but exhibited the lowest bulk density. • In contrast, FMP-CSD samples possessed the highest levels of vitamin D3. • Sensory assessments and multivariate analyses suggested that the CSD is the best technique. To enhance the quality and functionality of milk powder, this study developed a functional milk powder (FMP) incorporating a basil seed hydrogel based, nanoemulsion loaded with saffron ( Crocus sativus L .) petals, an underutilized plant-based sidestream, and vitamin D₃. Conventional spray drying (CSD), freeze drying (FD), and Refractance Window drying (RWD) were comparatively applied to produce the FMP and assess their impact on physicochemical, functional, and sensory related attributes. The optimized nanoemulsion exhibited shear-thinning behavior, with an initial particle size of 211 nm and a zeta potential of −74.5 mV, indicating high colloidal stability. Among the dried powders, FMP produced by FD showed the highest antioxidant capacity (75.16% RSA), approximately 14.2 higher than the non-functional sample, although it exhibited the lowest bulk density (464.5 kg/m³). In contrast, CSD-derived FMP retained the highest vitamin D₃ content (115.63 IU), nearly 20 folds greater than the non-fortified spray‑dried milk powder, which was associated with its smaller particle size (1302 nm). Sensory evaluation combined with multivariate analyses, including correlation analysis and principal component analysis (PCA), demonstrated that the drying method significantly influenced both nutritional functionality and sensory related properties of the powders. The results highlight the potential of integrating plant based sidestreams into functional dairy ingredients and demonstrate that the selection of drying technology plays a critical role in balancing bioactive retention, powder functionality, and consumer relevant quality attributes.