A comparative analysis of different extraction solvent systems on the extractability of eicosapentaenoic acid from the marine eustigmatophyte Nannochloropsis oceanica

Omega-3 fatty acid rich microalgal oil is currently gaining attention as a sustainable and promising alternative to other sources. This work aims to evaluate the recovery of eicosapentaenoic acid (EPA, C20:5n3) from Nannochloropsis oceanica by means of six different solvent systems including a classic system such as chloroform:methanol along with four other non-toxic mixes. The total lipids and lipid classes are also assessed along with the fatty acid profiles. Despite the high lipid content in chloroform:methanol (1:2); hexane:methanol (3:2) and dichloromethane:methanol (2:1), solvent systems result in higher amounts of EPA recovery, thus making them a suitable choice for extracting EPA compared to toxic solvents such as chloroform. However, an extensive comparative analysis was needed to validate the extraction efficacy of these solvent systems for scaling-up the process. Furthermore, the pigment profile of N. oceanica extracted using different extracts is also evaluated in this study.