Reducing Power of Seaweed Extracts

The reducing power of seaweed extracts was calculated by using ascorbic acid as standard. Different concentrations of seaweeds extracts (100–500 μg·mL⁻¹) were mixed with 1 mL of phosphate buffer (0.2 M, pH 6.6) and 1 mL of K₃Fe(CN)₆ (10 mg·mL⁻¹) and was then incubated for 20 min at 50 °C in water bath (Julabo, Seelbach, Germany). The reaction was ended by addition of 1 mL of TCA (100 mg L⁻¹) in the reaction mixture. Supernatant was collected after centrifugation at 7000× g for 10 min at room temperature. Freshly prepared FeCl₃ (0.1%, w/v) was mixed with collected supernatant and incubated for 10 min at room temperature. Absorbance was taken at 700 nm to calculate reducing power [34 (link),43 (link)].