Extraction of natural pigments from marine macroalgae waste

The need to replace synthetic pigments and the richness of marine macroalgae in natural pigments make their study relevant as a source of such valuable compounds. In the present study, marine macroalgae waste collected at a Northern Portugal beach was used aiming pigments extraction. Saccorhiza polyschides (brown algae) was the most abundant specie. The biomass (freeze-dried and ground to <1 mm) was subjected to pigments extraction using six different solvents and their amounts were evaluated through their maximum absorption using UV spectrophotometry. The results showed as promising the use of marine macroalgae waste as a natural source of pigments and acetone as the best solvent for extraction, followed by methanol. Chlorophyll a was found as the predominant pigment in the biomass with a maximum of 1685 μg g−1 extracted using 90% acetone. Carotenoids and fucoxanthin could also be extracted with methanol (174 μg g−1) and DMSO (252 μg g−1), respectively.