Macroalgae as an alternative source of nutrients and compounds with bioactive potential

The consumption of macroalgae has increased in occidental countries, favoured by the excellent nutritional properties of their food products and the bioactive properties attributed to them. The present work aims to analyse the nutritional values, the composition in fatty acids, organic acids and carotenoids of several macroalgae species: Codium tomentosum; Himanthalia elongata; Laminaria ochroleuca.; Saccharina latissima; Undaria pinnatifida; Porphyra sp. and Palmaria palmata. Furthermore, the antioxidant and antimicrobial properties were assessed. Regarding the composition of the macroalgae, the levels of proteins (which ranged between 6 and 30 g/100 g of dry weight (dw) for S. latissima and Porphyra sp., respectively) and the low levels of lipids (below 1 g/100 g dw for all the species) stand out. In the case of carotenoids, lycopene and Chlorophyll a were detected in all samples, with the highest values observed in C. tomentosum (11.2 and 56.3 mg/100g dw, respectively), while P. palmata showed the lowest content (0.32 mg and 1.5 mg/100g dw, respectively). Regarding antioxidant activity, OxHLIA assay was employed. EC50 values varied between 1.7 and 650 μg/mL for L. ochroleuca and P. palmata. H. elongata presented the greatest antibacterial potential (minimal bactericidal concentrations between 0.5-2 mg/mL) while L. ochroleuca showed the best antifungal effects (2 – 4 mg/mL). These species have good nutritional values and present interesting bioactivities. Thus, the incorporation of this macroalgae into the daily diet could provide nutritional and health benefits to the consumers. In addition, they could be used as a source of compounds for the nutraceutical, cosmetic of pharmaceutical industries.