A Comparative Study on Macronutrients Content and Antioxidant Activity of Four Wild and Cultivated Seaweeds from the Moroccan Atlantic Coast

Abstract

ABSTRACT: Extensive harvest of seaweeds in Morocco has caused overexploitation of these resources. Four Moroccan common seaweed species, wild and cultivated, were studied to assess the cultivated species' potential in comparison to their wild counterparts. The macronutrient composition, total phenolic compounds (TPC), as well as potential antioxidant activity (DPPH and FRAP), were established. Seaweeds contained a wide range of proteins (5–16% of DW), lipids (1–3% of DW), carbohydrates (20–59% of DW), and total polyphenols (3-6 mg EAG/g of DW). Red seaweeds contained high levels of polysaccharides (47–59% of DW), mainly the cultivated Gigartina pistillata, and important amounts of proteins, especially Gelidium sesquipedale (14–15% of DW), whereas the cultivated type was richer in proteins. Gracilaria gracilis and wild Gelidium sesquipedale are characterized by notable antioxidant activity, particularly the cultivated Gracilaria gracilis (TPC: 6.807 mg GAE/g of DW; low values of IC50 of DPPH: 53.863μg/mL and FRAP: 67.033μg/mL). Besides, the green seaweed Ulva lactuca is poor in carbohydrates but contains essential amounts of proteins and phenolics. This work highlights the significant potential of cultivating Moroccan seaweeds through algaculture to achieve more sustainable production with enhanced nutrient and bioactive molecule content.