Fatty Acid Profile in Field-Collected Seaweed, Lipid Extraction Optimization, and Food Functional Properties

Macroalgae (seaweeds) represent a sustainable and alternative source of high-value fatty acids (FAs), including omega-3 (n-3) and omega-6 (n-6), which could help alleviate pressure on wild fish stocks and mitigate global overfishing. This study analyzed the FA composition of field-collected red (Chondracanthus acicularis, Ballia callitriche, Gracilaria sp., and Gelidium coulteri), brown (Padina pavonica, Sargassum vulgare, Cystoseira myrica, Cystoseira sp., Dictyota dichotoma, and Stephanocystis mundane), and green seaweeds (Ulva compressa). Additionally, lipid extraction was optimized using food-grade solvents, reaction temperatures, and the functional properties of selected green and brown seaweeds. The results showed that brown and green seaweeds contained higher total FA content than red seaweeds, with a favorable n-6/n-3 ratio below 10. The selected species’ functional properties (Water- and Oil-Holding Capacities, Swelling Capacity) met food-grade standards. Ethyl acetate at 60 °C was identified as the optimal food-grade solvent for lipid extraction. Functional properties varied significantly by species and processing conditions, with Ulva compressa exhibiting superior Water- and Oil-Holding Capacities and Swelling Capacity compared to Cystoseira myrica, highlighting its potential as a functional food ingredient. These findings support using seaweeds as a sustainable source for human nutrition.