Solvent-Free Oil-Based Extraction and Microencapsulation of Lutein from Marigold (Calendula officinalis)

Lutein is a highly unstable antioxidant traditionally extracted using toxic solvents. To address this, this study evaluates the microencapsulation of marigold (Calendula officinalis) lutein utilizing a solvent-free, oil-based extraction approach as a potentially greener alternative to conventional organic solvent extraction. Lutein was extracted via Soxhlet, ultrasound-assisted extraction, and oil extraction using sunflower, corn, and grape seed oils. Emulsions were formulated with maltodextrin combined with gum arabic, tapioca starch, or waxy maize starch, and spray-dried. The resulting microcapsules demonstrated favorable moisture contents (0.98% to 3.43%) and high solubility (70.5% to 85.81%). Encapsulation efficiency ranged from 34.98% to 56.59%, peaking in formulations utilizing waxy maize starch and sunflower oil. Flowability was restrictive across all powders, indicated by elevated Carr's Compressibility Index values. Scanning electron microscopy revealed predominantly smooth, spherical particles measuring less than 6 µm. Notably, while unencapsulated sunflower oil extract exhibited the highest lutein concentration, microcapsules containing grape seed oil showed relatively higher lutein concentration in the final product. This observation may be related to differences in oil composition; however, further studies are required to confirm the underlying mechanisms.