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

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 TE g-1 of protein and an ACE inhibition with an IC50 of 379 µg protein mL-1 . The hydrolysate B showed 60% ± 1.8% of protein, antioxidant activity of 775 ± 13.0 µmol TE g-1 of protein and an ACE inhibition with an IC50 of 239 µg protein mL-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.

A Single Dose of Marine Chlorella vulgaris Increases Plasma Concentrations of Lutein, ß-Carotene and Zeaxanthin in Healthy Male Volunteers.

The beneficial health effects of Chlorella vulgaris have been associated with the presence of several nutrients and antioxidants, including carotenoids. However, the in vivo bioavailability of Chlorella is still poorly evaluated. In this work, a human intervention study was conducted in 11 healthy men to evaluate the bioavailability of carotenoids within 3 days after the intake of a single dose (6 g) of dried marine Chlorella vulgaris containing lutein (7.08 mg), ß-carotene (1.88 mg) and zeaxanthin (1.47 mg). Subjects were instructed to follow a low carotenoid diet during the experimental phase, starting 1 week earlier. On the day of the experiment, dried microalgae formulated in vegetarian hard capsules were ingested, and blood samples were collected up to 72 h for the analysis of plasma carotenoids concentration by high-performance liquid chromatography with diode-array detection. For all carotenoids, the estimated AUC and Cmax values were significantly different from zero (p < 0.05), indicating that a single dose of marine Chlorella vulgaris increased plasma concentrations of lutein (Cmin-corrected AUC = 1002 µg·h/L, Cmax = 20.4 µg/L), ß-carotene (AUC = 1302 µg·h/L, Cmax = 34.9 µg/L) and zeaxanthin (AUC = 122.2 µg·h/L, Cmax = 3.4 µg/L). The bioavailability of other compounds, namely, polyunsaturated fatty acids and trace elements, was also assessed post-prandial for the first time, showing that linoleic acid, docosahexaenoic acid and iodine were absorbed after microalgae intake. These findings support the use of Chlorella vulgaris as a source of carotenoids, PUFA and essential trace elements with associated health benefits.