Opuntia ficus-indica mucilage and maltodextrin systems as wall materials for canthaxanthin microencapsulation by spray drying

Opuntia ficus-indica mucilage is a natural polysaccharide with technological properties that make it a promising alternative for food applications. This study aimed to extract mucilage from Opuntia ficus-indica cladodes and to evaluate its use, in combination with maltodextrin, as wall materials for the microencapsulation of canthaxanthin by spray drying. The process yield, encapsulation efficiency, total carotenoid content, physicochemical, morphological, thermal properties, and antioxidant capacity of the produced microcapsules were evaluated. The average drying yield was 32.25%, and the encapsulation efficiency ranged from 62.99% to 64.11%, with total carotenoid content between 12.54 and 12.68 μg g⁻¹. The microcapsules exhibited high solubility (≈ 93%) and low water activity (av < 0.13). The instrumental color analysis indicated high chromatic saturation and predominance of reddish and yellowish hues attributed to canthaxanthin. Microstructural characterization by scanning electron microscopy revealed spherical, homogeneous particles with smooth surfaces and low roughness. The antioxidant capacity determined by the ABTS assay was 94.61% and remained partially preserved after microencapsulation. Functional groups analysis evidenced physical interactions such as hydrogen bonding and van der Waals forces among mucilage, maltodextrin, and canthaxanthin. Thermal analyses (TGA and DSC) demonstrated matrix stability up to 300 °C, confirming its protective effect. Therefore, the combination of Opuntia ficus-indica cladode mucilage and maltodextrin as wall materials proved effective for producing canthaxanthin microcapsules, indicating potential application in functional foods and bioactive delivery systems.