NUTRACEUTICAL CHARACTERISTICS AND BIOACTIVE COMPONENTS OF THREE SEAWEED SPECIES FROM SULU AND ILOCOS NORTE, PHILI

Abstract

This  study aimed  to determine the  nutraceutical composition  and properties of three selected  marine seaweeds: Ulva reticulata, Halymenia durvillei and Sargassum cristaefolium from Patikul Higad, Patikul, Sulu and  Paayas, Burgos, Ilocos Norte. The proximate and heavy metal composition of the seaweeds were determined. Qualitative phytochemical screenings were done. Antimicrobial assay of the algal extracts were tested against pathogens, Escherichia coli and

Staphylococcus aureus using paper diffusion. Antioxidant properties of seaweed extracts were assessed using diphenyl-p-picrylhydrazyl. Nutritional proximate composition of seaweeds in this study revealed that the brown seaweed  (i.e. S. cristaefolum) collected from Patikul, Sulu had highest average composition in terms of moisture, lipids, and total soluble solids while seaweeds from Burgos, Ilocos Norte had highest content of protein (for U. reticulata), carbohydrate (for H. durvillei), ash (for H. durvillei) and sodium (for H. durvillei). This varying results on nutritional proximate composition of the same species of seaweed in two collection sites maybe due to the effect of geographical location, time of collection and the weather condition.

Heavy metal analysis in seaweeds showed that zinc registered highest concentration  (328.74 mg/kg) in U. reticulata growing in Burgos, Ilocos Norte. Other evaluated seaweed species registered lower concentrations of copper (Cu), mercury, and lead indicating that they could be eaten as source of Cu. Antimicrobial property of seaweeds revealed in this study that S. cristaefolium of Patikul, Sulu and Ilocos Norte has active zone of inhibition on E. coli and S. aureus. The S. cristaefolium of Ilocos Norte has 5.19±0.52 mm; S. cristaefolium of Sulu has

13.35±0.84mm; and H. durvillei of Sulu has 5.98± 1.09 mm zone of inhibition for E. coli while U. reticulata of

Ilocos Norte and Sulu had no effect on the bacterial pathogens. Maximum activity of

1. cristaefolium of Ilocos Norte has 4.68± 3.53 mm and S. cristaefolium of Sulu has 15.79 ±0.30 mm inhibition zone against S. aureus. Halymenia durvillei of Ilocos Norte and Sulu, and U. reticulata of Ilocos Norte Sulu have no activity against S. aureus.

Dried samples of U. reticulata of Burgos, Ilocos Norte showed best antioxidant activity while S. cristaefolium had least antioxidant activity. Among the seaweeds, the green seaweed, U. reticulata exhibited the highest free radical scavenging activity while S. cristaefolium had the lowest. The results show that the scavenging activity  of the seaweeds on the DPPH radical was dependent on concentration. The phytochemicals responsible for the bioactivities could be attributed to the saponins, terpenes, tannins, steroids, anthraquinones, phenols and flavonoids present in the seaweeds.

In conclusion, the seaweeds screened in this study possess phytochemicals, antioxidants, and antimicrobial potentials, which may be considered for future applications in medicine, cosmetics and feed industry. In the next  research studies, further investigation should be undertaken to characterize the active compounds present in these types of seaweed as well as to evaluate the effects of each individual compound in fish and microorganism.