Abstract:

Seaweeds represent an underutilized marine resource with significant economic and nutritional potential. The global seaweed industry is valued at approximately US$5.5-6 billion annually and is primarily driven by applications in food products and phycocolloid extraction. Red macroalgae are particularly valuable due to their high concentrations of polysaccharides, including agar, which functions as a natural hydrocolloid and dietary fiber. Agar has been widely used as a gelling agent in food systems and has also been investigated for potential health benefits related to digestion, satiety, and metabolic regulation. Because of its high fiber content and low caloric value, agar has been explored as a functional ingredient in dietary supplements and weight-management products. This study evaluates the feasibility of extracting agar from red algae using a simplified laboratory protocol adapted from established extraction methods. Collected seaweed biomass was cleaned, dried, and chemically pretreated before undergoing hot-water extraction to solubilize agar. The extract was filtered, allowed to gel during cooling, and subsequently dehydrated through UV bleaching to remove excess water. The resulting gel was dried to obtain crude agar. Agar yield was calculated relative to the dry mass of the original seaweed material. Preliminary results demonstrated successful formation of agar gels following extraction, confirming the presence of agar-forming polysaccharides within the sampled red algae. These findings highlight the potential of red seaweeds as a source of functional hydrocolloids and support further research exploring their nutritional properties, food applications, and potential role in sustainable aquaculture-based food systems.