Pressurized liquids, PLE, and enzyme-assisted extraction, EAE, have been tested to improve the extraction
of phlorotannins from the seaweed Sargassum muticum. Enzymatic treatment with proteases and carbo-
hydrases, alkaline hydrolysis and PLE with ethanol:water as extracting solvent have been studied in
terms of extraction yield, total phenolic content and antioxidant activity (TEAC assay). Results demon-
strated that the application of PLE alone provided the highest yields and relevant antioxidant activity.
An experimental design was employed to further optimize the PLE extraction conditions; optimum
parameters included the use of 160 ?C and 95% ethanol. Under these conditions, values of 21.9%,
94.0 mg gallic acid equivalents g ?1 , 5.018 mg phloroglucinol equivalents g ?1 and 1.275 mmol trolox
equivalents g ?1 were obtained for extraction yield, total phenols, total phlorotannins and TEAC, respec-
tively. A preliminary chemical characterization by liquid chromatography coupled to mass spectrometry
provided insight in terms of the mechanisms involved in the different processes.