Authors

Xyza Krsitina None. Billones

Author

Maria Alma None. Quiao

Co-author

Elnor C. Roa

Co-author

Proserpina G. Roxas

Co-author

Mindanao State University at Naawan, 9023 Naawan, Misamis Oriental, Philippines

*Corresponding author: [email protected]

ABSTRACT

Seaweeds are exposed to large amounts of environmental stressors which favor the generation of free radicals. To mitigate oxidative damage during these adverse conditions, these organisms produce powerful antioxidants. This study therefore seeks to investigate the potentiality of three Kappaphycus cultivars as natural sources of antioxidants. Antioxidant potential was evaluated by the basis of DPPH radical scavenging and ferrous ion chelating activities. The aim is to take advantage the presence of their antioxidants that can be significant for coastal community nutrition and for future economic commercialization. Results revealed that methanolic extracts from different Kappaphycus cultivars have exhibited good radical scavenging and chelating activities ranging from 24-37% at 1000 mg mL-1 and 31-57% at 7 mg mL-1, respectively. NE monsoon grown cultivars have shown better antioxidant activity wherein the green “Sacol” strain possessed the highest DPPH radical scavenging activity while the reddish brown “Tambalang” strain showed the highest chelating activity. The differences in radical scavenging and chelating activities, however, did not significantly vary among cultivars and between monsoon seasons. The obtained IC50 values of antioxidant activities are lower compared to the reported values of other studies. Nevertheless, this provides good information considering that the extracts were derived from natural sources. Seawater temperature is the sole factor that showed the highest significant association to the radical scavenging and chelating activities of the cultivars. As part of a balanced diet, regular consumption of seaweeds will not only provide basic dietary benefits but also offers the goodness of their anticipated antioxidant capacities. To ensure traceability and high level of food safety and security, seaweeds destined for human consumption must be ideally derived from pristine, managed and sustainable resources. Further studies are strongly encouraged to validate the results as the findings of this study are not yet conclusive.