Green extraction of carotenoids from Spirulina subsalsa and Chlorella vulgaris using natural deep eutectic solvents

Abstract

Carotenoids from microalgae, including β-carotene, lutein, and astaxanthin, have significant potential for food and healthcare applications due to their antioxidant properties. Increasing demand for these pigments necessitates greener extraction methods. Natural deep eutectic solvents (NADES) have emerged as promising green solvents that could replace conventional organic solvents. This study investigates the extraction and quantification of β-carotene, lutein, and astaxanthin from Chlorella vulgaris and Spirulina subsalsa using a range of NADES to identify efficient, nontoxic solvent extraction methods suitable for functional food development. High-performance liquid chromatography (HPLC) was used for quantification. The lactic acid:1,2-propanediol (LAPo) system showed the highest extraction efficiency for carotenes in both species. β-Carotene extraction reached 73% in C. vulgaris and 97.63% in S. subsalsa. Lutein extraction reached 61% in C. vulgaris and 98% in S. subsalsa. Astaxanthin extraction reached 36% in C. vulgaris and 43% in S. subsalsa. For S. subsalsa strain Z15, NADES performed comparably to traditional solvents. This research highlights the potential of NADES as eco-friendly alternatives for carotene extraction and supports their application in scalable functional food production. Gelatin matrices incorporating microalgal carotenoids were also developed to evaluate color stability and related properties.