Production and Characterization of a Bioactive Rich Extract from the Macroalga Pyropia orbicularis for the Development of Novel Functional Ingredients

Macroalgae are a valuable source of bioactive substances, particularly phenolic compounds with antioxidant properties. However, conventional extraction methods frequently rely on non-GRAS solvents, limiting their applicability in food and nutraceutical products. This study aimed to develop a Pyropia orbicularis extract enriched in bioactive compounds and antioxidant activity using GRAS solvents through a solid–liquid extraction process. Response surface methodology was employed to optimize the extraction process using total phenolic content (TPC) and FRAP assay as response variables. The selected maceration conditions were 80% ethanol, 55 °C, an algae-to-solvent ratio of 1:29.4 (g/mL), and 40 min of stirring. The resulting dried extract exhibited a TPC of 106.9 ± 3.5 mg GAE/g, a flavonoid content of 12.4 ± 0.3 mg QE/g, and antioxidant capacities of 50.0 ± 2.2 µmol TE/g by FRAP and 500.1 ± 8.9 µmol TE/g by ORAC. HPLC-MS analysis revealed a chemically diverse profile, with major compounds tentatively identified as amino acid derivatives, lipids, and organic acids. No cytotoxicity was observed in Caco-2 or HT-29 cells at concentrations up to 1000 µg/mL. Overall, the optimized extraction strategy enabled the recovery of a bioactive-rich extract from P. orbicularis, supporting its further investigation as a potential ingredient for food-related applications.