Effect of Drying Methods on Lutein Content and Recovery by Supercritical Extraction from the Microalga <i>Muriellopsis</i> sp. (MCH35) Cultivated in the Arid North of Chile

• Main Authors: Mari Carmen Ruiz-Domínguez, Paola Marticorena, Claudia Sepúlveda, Francisca Salinas, Pedro Cerezal, Carlos Riquelme
• Format: Article
• Language: English
• Published: MDPI AG 2020-10-01
• Series: Marine Drugs
• Subjects: microalgae; <i>Muriellopsis</i>; spray drying; freeze-drying; lutein; supercritical fluid extraction
• Online Access: https://www.mdpi.com/1660-3397/18/11/528

In this study, we determined the effect of drying on extraction kinetics, yield, and lutein content and recovery of the microalga <i>Muriellopsis</i> sp. (MCH35) using the supercritical fluid extraction (SFE) process. The strain was cultivated in an open-raceways reactor in the presence of seawater culture media and arid outdoor conditions in the north of Chile. Spray-drying (SD) and freeze-drying (FD) techniques were used for dehydrating the microalgal biomass. Extraction experiments were performed by using Box-Behnken designs, and the parameters were studied: pressure (30–50 MPa), temperature (40–70 °C), and co-solvent (0–30% ethanol), with a CO₂ flow rate of 3.62 g/min for 60 min. Spline linear model was applied in the central point of the experimental design to obtain an overall extraction curve and to reveal extraction kinetics involved in the SFE process. A significant increase in all variables was observed when the level of ethanol (15–30% <i>v/v</i>) was increased. However, temperature and pressure were non-significant parameters in the SFE process. The FD method showed an increase in lutein content and recovery by 0.3–2.5-fold more than the SD method. Overall, <i>Muriellopsis</i> sp. (MCH35) is a potential candidate for cost-effective lutein production, especially in desert areas and for different biotechnological applications.