Atmospheric cold plasma pretreatment for enhanced phlorotannin extraction and bioactivity from Sargassum tenerrimum

The effects of dielectric barrier discharge atmospheric cold plasma (ACP) pretreatment on enhancing the extraction of phlorotannins (PHT) from water-suspended Sargassum tenerrimum powder were investigated. The optimization of process conditions was conducted using the one-factor-at-a-time method, focusing on variables such as water volume (20, 30, and 40 mL), exposure time (5, 10, and 15 min), and input power (50, 70, and 80 W). Results indicated that suspending seaweed powder in 20 mL of distilled water for 10 min at 80 W increased the PHT content from 3.42 ± 0.23 to 6.65 ± 0.29 mg phloroglucinol equivalent per gram of extract. Scanning electron microscopy (SEM) revealed progressive damage to the seaweed cell structure. HPLC analysis demonstrated alterations in the PHT component profiles following ACP pretreatment. Furthermore, biological activities, including antibacterial and anti-inflammatory properties, improved after ACP pretreatment without exhibiting cytotoxic effects. These results suggest that the ACP pretreatment developed can effectively enhance the extraction of bioactive compounds, increasing both their yield and biological efficacy. • Cold plasma enhanced phlorotannin extraction efficiency from Sargassum tenerrimum. • Improved antioxidant, antibacterial, and anti-inflammatory activities post-treatment. • Cold plasma treatment led to the formation of phlorotannin derivatives with higher bioactivity. • Cold plasma treatment showed no cytotoxic effects on the extracted phlorotannins.