Seasonal Variation in Nutritional Composition and Antioxidant Potential of Gelidium corneum from the Doukkala Coast, Morocco

The coastal areas of Doukkala, Morocco, are recognized for its abundant populations of Gelidium corneum, an acknowledged red alga used for agar production. This study focused the valorization of G. corneum beyond agar extraction, focusing on its nutritional composition, antioxidant properties, and socio-economic significance. Seasonal changes in biochemical composition were analyzed by measuring ash, crude protein, total lipid, and carbohydrate contents throughout the year.The antioxidant capacity of aqueous algal extracts was evaluated seasonally using DPPH, ABTS, and FRAP assays, along with total phenolic content (TPC). Results indicated that the biomass contained substantial amounts of protein (up to 19.22 ± 0.13%) and carbohydrates (up to 43.9 ± 0.07%), while lipid content remained relatively low (up to 2.37 ± 0.7%), particularly in autumn. Moderate antioxidant activity was observed, with DPPH inhibition reaching 14.44 ± 0.12%, ABTS inhibition 20.55 ± 0.18%, FRAP 1.66 ± 0.35 mg AAE g -1 , and TPC 12.34 ± 0.28 mg GAE g -1 . These findings underscore the value of G. corneum as a natural resource with both nutritional and functional potential, supporting its prospective use in food applications while contributing to the socio-economic development of the Doukkala region.