Antioxidant Activity of Brown Algae CO2 Extracts and Lipid Stability

Vegetable oils are susceptible to oxidation during storage, which is a serious problem for shelf-life and food safety. The article describes the antioxidant properties of supercritical extracts from brown algae (Undaria pinnatifida and Costaria costata), Russian Far East. It also explains their prospects as stabilizers that preserve the quality and safety of vegetable oils by affecting the kinetics of oxidation and hydrolysis. The study featured supercritical extracts of marine brown algae Undaria pinnatifida and Costaria costata from Russian Far East. The methods involved spectrophotometry and high-performance liquid chromatography. Supercritical extracts of marine brown algae proved to be reliable sources of bioactive substances, e.g., phenolic compounds, carotenoids, and mannitol. They also possessed antioxidant properties in terms of antiradical activity, hydroxyl ion binding, superoxide radical absorption, and Fe+2 chelating. The experiments revealed nine phenolic compounds responsible for antioxidant properties. The supercritical extract of Costaria costata demonstrated a greater antioxidant effect on lipid oxidation in vegetable oils than Undaria pinnatifida. Both algae proved effective in stabilizing hydrolysis and were able to increase the shelf-life of soy and sunflower oils by three months. Supercritical extracts of Undaria pinnatifida and Costaria costata served as antioxidants to stabilize lipid oxidation in refined and unrefined soy and sunflower oils. The research revealed high approximation coefficients for regression equations describing the patterns of changes in the peroxide and acid numbers of vegetable oils stabilized with supercritical extracts of these marine brown algae.