Sustainable production of eicosapentaenoic acid-rich emulsion from Nannochloropsis gaditana by nitrogen regulation and physical cell disruption.

Nannochloropsis gaditana is a promising novel food ingredient; however, its utilization remains limited due to its rigid bilayer cell wall. In this study, co-enrichment of eicosapentaenoic acid (EPA) and protein was achieved by supplementing with 1.76 mmol/L NaNO3, yielding biomass enriched with functional nutrients. N. gaditana emulsions were prepared using three cell disruption methods: high-pressure microfluidization (HPM), ultrasonication (US), and bead milling (BM). HPM-treated emulsions showed the highest release of soluble protein (2.52 g/100 mL), lipids (0.53 g/100 mL), and EPA (0.27 g/100 mL), along with higher ζ-potential values (-42 mV) and reduced creaming. Sensory evaluation, colorimetry, electronic tongue analysis, and GC-MS profiling indicated the superior sensory characteristics of HPM emulsions, with bright green color, balanced umami-salty flavor, and distinctive grassy aroma. In vitro digestion confirmed improved EPA bioaccessibility in emulsions prepared using HPM and US. Overall, this study offers an efficient and sustainable strategy for producing functional EPA-rich emulsions.