Deep Eutectic Solvents for Astaxanthin Extraction from Haematococcus Pluvialis: Recent Advances

Objective: This study evaluates recent advances in deep eutectic solvent (DES) systems for astaxanthin extraction from Haematococcus pluvialis, comparing their efficiency and limitations. Theoretical Framework: The review synthesizes knowledge on H. pluvialis biology and astaxanthin biosynthesis, limitations of physical/chemical extraction methods, and DES design principles for algal biorefining. Method: A systematic literature review was conducted in Web of Science databases using search terms aligned with the research objectives. Selected articles were analyzed according to inclusion/exclusion criteria to compose the discussion. Results and Discussion: Recent DES innovations have transformed astaxanthin extraction from H. pluvialis, achieving 83-99.6% yields under mild conditions (25-50°C). Hydrophobic DES (thymol-oleic acid) demonstrated dual extraction-stabilization functions, while IL-DES hybrids enabled selective fractionation. Aqueous DES-ATPS systems reached 99.6% efficiency through targeted cell wall disruption, and acidic DES (menthol-acetic acid) combined 91.3% recovery with extended extract stability. Research Implications: The reviewed advances position DES as sustainable alternatives for industrial astaxanthin production, offering integrated extraction-stabilization processes and biorefinery potential through biomass valorization. GRAS-compliant formulations address safety concerns, though future work should optimize solvent viscosity. Originality/Value: This is the first comparative analysis of DES systems for H. pluvialis biorefining, providing design guidelines for industrial implementation.