Macroalgae are increasingly recognised as promising sources of bioactive compounds with nutritional and functional relevance. This study investigated the biochemical composition of selected green, brown, and red marine macroalgae from the Mediterranean coast sampled at different seasons, focusing on fatty acid profiles, carotenoid composition, phenolic and flavonoid contents, antioxidant activity, and multivariate biochemical structuring. Fatty acid distributions were determined by Gas Chromatography (GC)-Flame Ionisation detector (FID), carotenoids were quantified and profiled by Liquid Chromatography–Mass Spectrometry (LC-MS), and total phenolic content, total flavonoid content, and antioxidant capacity (ABTS•+ and DPPH• methods) were assessed using standard spectrophotometric assays. Principal component analysis was applied to evaluate relationships among biochemical variables and taxonomic patterns. Brown macroalgae tended to exhibit more complex and enriched biochemical profiles, containing high proportions of long-chain n-3 polyunsaturated fatty acids, particularly eicosapentaenoic acid, elevated total carotenoid contents dominated by fucoxanthin, the highest total phenolic and flavonoid contents, and antioxidant activities. Green macroalgae were characterised by fatty acid profiles rich in saturated and C18 polyunsaturated fatty acids, while carotenoid compositions were dominated by lutein and siphonoxanthin. Red macroalgae exhibited comparatively simpler lipid and pigment patterns, characterised by palmitic acid and zeaxanthin as dominant components and lower total carotenoid levels. Principal component analysis revealed taxonomic structuring, with brown algae clearly separated from green and red groups, while seasonal differences were minor. Antioxidant activity closely clustered with carotenoids and total phenolic content, suggesting their combined contribution to radical-scavenging capacity. Overall, brown species appear as promising candidates for functional foods and nutraceutical applications.
Prates et al. (Thu,) studied this question.