Proline content of the G. acerosa and S. wightii was determined
by Bates [13]. 1.25 g of ninhydrin was added to 30 ml of glacial acetic acid in a test tube containing 20 ml of 6 M of phosphoric acid. The mixture was agitated till it dissolved and the solution was kept at 4◦C, which is stable for 24h. 0.5g of seaweeds were placed in 10 ml of 3% aqueous sulphosalicylic acid and filtered with Whatman no 1 or 2 filter paper. 2 ml of filtrate and 2 ml of acid ninhydrin was mixed with 2 ml of glacial acetic acid. The mixture was kept at 100 ◦ C for 60 min. The reaction was terminated by placing the mixture in ice bath. After that, the mixture was extracted with toluene. The solution was mixed vigorously with the test tube stirrer. Chromophore containing toluene was collected from the aqueous phase and warmed at room temperature and the absorbance was measured at 520 nm using UV-Vis spectrophotometer. Proline was used as standard and the experiments were done in triplicates.