Comparison of Total Phenolic Content and Antioxidant Activity of Kappaphycus alvarezii from Langkawi and Semporna

The total phenolic content and antioxidant activity of Kappaphycus alvarezii obtained from Langkawi, Kedah and Semporna, Sabah were evaluated. The total phenolic content (TPC) of the extracts were determined according to the Folin Ciocalteau method and results were expressed as gallic acid equivalents. The antioxidant activities of the extracts were determined by three methods namely Free Radical Scavenging Activity (DPPH), Ferric Reducing Antioxidant Power (FRAP) and Trolox Equivalent Antioxidant Capacity (TEAC). Both of the TPC and FRAP assays showed that seaweed from Semporna, Sabah significantly (p<0.05) had higher antioxidant activities compared to Langkawi, Kedah one (Semporna's seaweed: 73.25 mg GAE/100g and 16.94 mu mol TE/100g, Langkawi's seaweed: 54.35 mg GAE/100g and 10.01 mu mol TE/100 g). However, the seaweed from Langkawi (60.93 mu mol TE/100g) show higher TEAC value compared to seaweed from Semporna (36.36 mu mol TE/100g) but for DPPH assay there was no significant difference (p>0.05) between the samples. Pearson coefficient correlation test, showed that there was a positive correlation (p<0.01) between TPC and antioxidant activity (FRAP assay) (r=0.980) and thus it can be concluded that the phenolic compounds was a contributor of the antioxidant activity in Kappaphycus alvarezii.