Antioxidant compounds in edible brown seaweeds

Seaweeds are an excellent source of compounds with biological activity. Among the bioactive substances identified, antioxidants have received particular interest due to their beneficial effects on health. In the present study, the total phenolic content and the pigment contents in edible seaweeds were evaluated. The total phenolic content was determined by Folin-Ciocalteu's method for four species of brown algae included Himanthalia elongata, Laminaria sp., Laminaria saccharina and Undaria pinnatifida. The total polyphenol content varied between 1.3 and 10.0 g phloroglucinol/kg wet weight of sample. The components responsible of the colour (carotenoids and chlorophylls) of the seaweeds were evaluated by using a spectrophotometric method. In addition, pigments were separated and identified by on line HPLC coupled with UV-Vis and fluorescence detectors and confirmed by liquid chromatography coupled to mass spectrometry (LC-MS APCI). Fucoxanthin, beta-carotene, chlorophyll a and phaeophytin a were identified in the samples analysed.