Optimizing carotenoids NaHDES extraction for enhancing spreadable chocolate's nutritional value

The potential to directly fortify food products using extracts obtained through green solvents is both innovative and promising. In pursuit of this goal, this study evaluated the possibility of directly fortifying spreadable chocolate with an optimized carotenoid-rich Natural Hydrophobic Deep Eutectic Solvent (NaHDES) extract formulated with monoterpenes. The optimized extract (3.545 ± 0.126, 3.341 ± 0.023, and 0.049 ± 0.001 mg/mL for total carotenoids, β-carotene and lutein, respectively) was obtained using a thymol/DL-menthol molar ratio of 1:4, a solvent:sample ratio of 10 (v/w), and an extraction time of 30 min. Subsequently, commercial no-sugar-added spreadable chocolate was fortified with the selected extract at 14 and 28 % (v/w). The fortified products were analyzed for carotenoid content, antioxidant activity, physicochemical and textural properties. The findings revealed that the lower extract addition minimally impacts the investigated characteristics of spreadable chocolate. Considering the preserving effect of the selected NaHDES on carotenoids and antioxidant activity, this innovative approach holds great promise for enhancing fortified food products' nutritional value and stability. • Monoterpenes and carboxylic acids were utilized in formulating eleven NaHDESs. • Extensive physiochemical characterization of NaHDESs was conducted. • The optimized NaHDES-UAE allowed high carotenoid extraction. • The selected NaHDES preserves the stability of carotenoids better than acetone. • NaHDES extract effectively improves the spreadable chocolate nutritional value.