The impact of temperature on the antioxidant activity of fucoidan obtained from brown seaweed sargassum hystrix extracted using edta

The harmful side effects, including carcinogenesis and liver toxicity obtained from synthetic antioxidant consumption instigates the need to develop natural forms. In addition, brown seaweed is one of the potential resources for application as an alternative, due to the antioxidant potentials of the fucoidan compounds present. Therefore, this study is aimed at determining the impact of extraction temperature on the antioxidant activity of fucoidan from Sargassum hystrix extracted using EDTA. The extraction process was performed using 0.5 EDTA at 50, 70, and 90oC, and the fucoidan characteristics was evaluated for yield, total carbohydrate, sulfate content and also through Fourier-transform infrared (FTIR) analysis. Furthermore, the antioxidant activity was measured using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity (RSA), ferric reducing antioxidant power (FRAP), hydroxyl radical scavenging activity (HRSA), and total antioxidant capacity (TAC). The results showed a S. hystrix fucoidan yield of 1.18±0.15 to 2.94±1.06, with total sugar content at 38.05±15.58 to 52.06±8.11, and 7.54±1.91 to 27.80±3.59 for sulfate. Moreover, FTIR analysis demonstrated the existence of sulfate and ester functional groups in the molecule, and served as a confirmatory assay for fucoidan. The antioxidant activity of S. hystrix fucoidan was evaluated at varied temperatures (50, 70, and 90o C) while using the DPPH method, and IC50 values of 1249.81, 2200.32, and 1818.93 ppm were obtained respectively. Meanwhile, 135.54, 71.38, and 88.04 µM g-1 were correspondingly recorded with FRAP, while HRSA showed 1464.55, 2360.00, and 1054.22 ppm, and 232.79, 374.82, and 377.53 mg AAE g-1 were respectively obtained with TAC. The antioxidant activity of fucoidan sourced from S. hystrix was similar or tended to be better than the commercial variety. Key Words:. © 2020, BIOFLUX SRL. All rights reserved.