Advanced Extraction of Lipids with DHA from <i>Isochrysis galbana</i> with Enzymatic Pre-Treatment Combined with Pressurized Liquids and Ultrasound Assisted Extractions

• Main Authors: María Señoráns, Natalia Castejón, Francisco Javier Señoráns
• Format: Article
• Language: English
• Published: MDPI AG 2020-07-01
• Series: Molecules
• Subjects: omega-3 PUFA; microalgae; advanced extraction techniques; pressurized liquid extraction (PLE); enzymatic pre-treatment; <i>Isochrysis galbana</i>
• Online Access: https://www.mdpi.com/1420-3049/25/14/3310

Microalgal biomass is a sustainable and valuable source of lipids with omega-3 fatty acids. The efficient extraction of lipids from microalgae requires fast and alternative extraction methods, frequently combined with biomass pre-treatment by different procedures. In this work, Pressurized liquid extraction (PLE) was optimized and compared with traditional lipid extraction methods, Folch and Bligh and Dyer, and with a new Ultrasound Assisted Extraction (UAE) method for lipids from microalgae <i>Isochrysis galbana</i>. To further optimize PLE and UAE, enzymatic pre-treatment of microalga <i>Isochrysis galbana</i> was studied with commercial enzymes Viscozyme and Celluclast. No significant differences were found for lipid yields among different extraction techniques used. However, advanced extraction techniques with or without pre-treatment are a green, fast, and toxic solvent free alternative to traditional techniques. Lipid composition of <i>Isochrysis</i> was determined by HPLC-ELSD and included neutral and polar lipids, showing that each fraction comprised different contents in omega-3 polyunsaturated fatty acids (PUFA). The highest polar lipids content was achieved with UAE (50 °C and 15 min) and PLE (100 °C) techniques. Moreover, the highest omega-3 PUFA (33.2%), eicosapentaenoic acid (EPA) (3.3%) and docosahexaenoic acid (DHA) (12.0%) contents were achieved with the advanced technique UAE, showing the optimized method as a practical alternative to produce valuable lipids for food and nutraceutical applications.