Bioactive compounds obtained via subcritical water hydrolysis of Ecklonia stolonifera: Characterization and potential application

Bioactive compounds were extracted from the brown seaweed Ecklonia stolonifera using subcritical water hydrolysis, a green extraction technique to valorize raw biomass. The reaction temperature for the hydrolysis ranged between 120 & DEG;C and 220 & DEG;C and the products were compared with those obtained by methanol extraction. Reaction temperature played a significant role in the release of active compounds such as sugars, phenolics, flavonoids, and antioxidants. The optimum extraction temperature was found to be 195 & DEG;C; at this temperature, the yield of reducing sugars was 61.83 & PLUSMN; 1.63 mg glucose, the total phenolic compound content was 26.02 & PLUSMN; 0.05 mg phloroglucinol, and the total flavonoid compound content was 8.40 & PLUSMN; 0.18 mg quercetin g(-1) of E. stolonifera sample on a dry weight basis. Six different phenolic compounds were identified by high performance liquid chromatography (HPLC), of which gallic acid was the most abundant. Hydrolysates obtained using subcritical water extraction possessed strong antioxidant and antimicrobial activities. The results of this study will be useful for further valorizing brown seaweeds in applications with potential benefits for humans.

Automated summary

Bioactive compounds were extracted from the brown seaweed Ecklonia stolonifera using subcritical water hydrolysis, which is a green extraction technique. The release of active compounds such as sugars, phenolics, flavonoids, and antioxidants was influenced by reaction temperature, with an optimum extraction temperature of 195°C. Six different phenolic compounds were identified, with gallic acid being the most abundant. The hydrolysates obtained exhibited strong antioxidant and antimicrobial activities. This study provides valuable insights for the further utilization of brown seaweeds in applications with potential benefits for humans.