Enzymatic hydrolysis allows an integral valorization of Nannochloropsis oceanica resulting in the production of bioactive peptide extracts and an eicosapentaenoic acid enriched fraction.

Abstract

Nannochloropsis oceanica is a microalga with relevant protein content, making it a potential source of bioactive peptides. Furthermore, it is also rich in fatty acids, with a special focus on eicosapentaenoic acid (EPA), an omega-3 fatty acid mainly obtained from marine animal sources, with high importance for human health. N. oceanica has a rigid cell wall constraining protein extraction, thus hydrolyzing it may help increase its components' extractability. Therefore, a Box-Behnken experimental design was carried out to optimize the hydrolysis. The hydrolysate A showed 67%±0.7% of protein, antioxidant activity of 1166±63.7 μmol TEg-1 of protein and an ACE inhibition with an IC50 of 379 μg proteinmL-1 . The hydrolysate B showed 60%±1.8% of protein, antioxidant activity of 775±13.0 μmol TEg-1 of protein and an ACE inhibition with an IC50 of 239 μg proteinmL-1 . The by-product showed higher yields of total fatty acids when compared to "raw" microalgae, being 5.22% and 1%, respectively. The sustainable developed methodology led to the production of one fraction rich in bioactive peptides and another with interesting EPA content, both with value-added properties with potential to be commercialized as ingredients for different industrial applications, such as functional food, supplements, or cosmetic formulations.