Comparative Yield and Physicochemical Properties of Marine Bioproduct Sodium Alginate from the Brown Seaweeds Hormophysa Triquetra and Carpomitra Costata

ABSTRACT This work intended to extract and quantify sodium alginate from brown algae Hormophysa triquetra ( H. triquetra ) and Carpomitra costata ( C. costata ) and to verify its purity with spectroscopic methods. Sodium alginate extraction using brown algal biomasses ( H. triquetra and C. costata ) produced 22.55% ± 0.74% and 26.8% ± 0.61%, respectively (dry weight). The extracted alginates showed pH values of 9.65 and 9.1, viscosities of 55.8 cP and 95.5 cP, and moisture contents of 12.5% and 9.2%. Carbohydrates, proteins, and lipids were 74.2 %± 1.5% and 82.5% ± 0.9%, 0.64% ± 0.2% and 0.85% ± 0.3%, and 0.5% ± 0.01% and 1.4% ± 0.1% for H. triquetra and C. costata , respectively. Phytochemical screening revealed the absence of alkaloids, terpenoids, steroids, tannins, flavonoids, phenols, glycosides, and phlorotannins, which confirmed the purity of the obtained sodium alginate. 1 H‐NMR and FTIR spectroscopic analyses further confirmed the structural features of the obtained sodium alginate especially from C. costata . The information provided indicates that high‐purity sodium alginate from C. costata and to a lesser extent H. triquetra are effective sources for further biotechnology and industrial applications.