Abstract:
Since phenolic compounds exhibit radical scavenging properties and there is a
co-relation between the phenolic content and the anti-oxidant properties, the
present study will identify the presence of phenolic compounds in four
varieties of Sargassum sp. available in southern coast of Sri Lanka, and the
possibilities of their food applications. Specimens were collected from
Hikkaduwa, and the cleaned samples were dried and grounded with cryogenic
grinding to form powder. Phenolic content analysis was conducted by Folin-
Ciocalteau method by using the 100% methanol extraction followed by
addition of Sodium Carbonate and incubation. Results were obtained by
measuring the absorbance at 765nm as a concentration of Gallic Acid
equivalent and four varieties Sargassum sp. portrayed a phenolic content of
6.2% ± 0.021, 3.7% ± 0.021, 3.4% ± 0.002, 2.7% ± 0.008 from the plants’ dry
weight respectively (With 1265mg/l GAE, 720mg/l GAE, 661mg/l GAE,
523mg/l GAE respectively). Upon identifying the phenolic content of the
seaweed, further analysis was conducted to assess the anti-oxidant activity of
the species. Methanol extractions of seaweeds were assessed for DPPH free
radical scavenging activity. All the four species exhibited a free radical
scavenging activity with species 01 demonstrating the highest activity of
21.7% ± 0.1 at the DPPH concentration of 100 μg/ml, against the control
sample. At the next stage, a cookie was formulated by inclusion of the seaweed
powder at 5% of each of the Sargassum sp. The free radical scavenging
activity of the seaweed was measured by evaluating the shelf life of the cookie,
with sensory parameters against the control. It was found that the cookie with
the powder of Sargassum sp 01 had the highest extended shelf life from 3
months totaling up to a shelf life of 6 months, where the control had only a 3-
month shelf life.
