Browsing by Author "Edirisinghe, K.E.A.N."

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    Comparative Study on Antioxidant Activity and Antimicrobial Activity of Sargassum ilicifolium Crude Extract Using Different Solvent Extractions
    (Uva Wellassa University of Sri Lanka, 2019-02) Edirisinghe, K.E.A.N.; Bogahawaththa, B.R.S.; Abeyrathna, E.D.N.S.; Ranasinghe, M.K.
    Seaweeds are used for food, pharmaceutical and biochemical applications as they possess interesting biological activities. Amongst seaweeds, brown seaweeds show excellent antimicrobial, antioxidant and antiviral properties. S. ilicifolium is an economically important, underutilized seaweed species where more research opportunities are available. Hence, the present study was conducted to determine the functional properties of crude extracts of S. ilicifolium to find the best extract to develop as an ingredient for food industry. Dried and coarsely powdered samples of S. ilicifolium were subjected to solvent extraction using methanol, ethanol, chloroform and acetone. The yield, proximate analysis of crude extracts was determined while antioxidant activity was determined using DPPH and TBARS assays. Antimicrobial activity was determined against the Staphylococcus aureus. Significantly highest extraction yield was recorded in methanolic extraction (17.18±3.20%) while 9.60±2.14%, 2.80±0.59%, and 3.60±0.37% yields were obtained from ethanol, acetone and chloroform extractions, respectively (P˂0.05). The highest carbohydrate (37.64±1.1%) and moisture (14.07±0.71%) were observed in methanolic crude extract. Highest ash content (37.15±4.90%) was observed in ethanolic crude extract. DPPH scavenging activity of the dried seaweed, methanolic and ethanolic crude extractions were 5.32±0.35%, 21.47±2.81%, 14.93±2.55% respectively (P˂0.05). The malonaldehyde produced in dried seaweeds, chloroform and acetone extractions were recorded higher while ethanolic, methanolic extractions were showed lower than control. Antimicrobial assay against S. aureus did not show resistant to all the seaweed extracts. Hence, it could be concluded that the presence of bioactive components in the crude exacts of S. ilicifolium while highest components in ethanolic and methanolic extracts. Therefore, the ethanolic extract of S. ilicifolium could be a potential source as an ingredient for food industry.
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    Development of an Edible Coating Using Crude Extract of Sargassum Ilicifolium
    (Uva Wellassa University of Sri Lanka, 2014) Edirisinghe, K.E.A.N.
    Edible films and coatings made up of plants like seaweeds have high demand in the world. S. ilicifolium is a brown seaweed that shows excellent antimicrobial, antioxidant and antiviral properties. Hence, the present study was conducted to develop gelatine based edible coating materials using crude extraction of S. ilicifolium and to determine its functional and physiochemical properties. Dried and coarsely powdered seaweeds were subjected to solvent extraction using methanol, ethanol, chloroform and acetone. The yield and proximate analysis of crude extracts were determined. The antioxidant activity was determined using DPPH and TBARS assays. Antimicrobial activity was determined by agar well diffusion method. Different concentrations of ethanolic extract of S.ilicifolitun which dissolved in water was incorporated with gelatin to make edible films and coatings. Transparency, water solubility, moisture content, density and colour were checked in films. Tuna fish samples were dipped in seaweed concentrated solutions and stored under freezing temperature (-18 °C). Its moisture loss, total plate count and TBARS was checked in 3-day time intervals. A sensory analysis was conducted to fish samples. Significantly highest extraction yield was obtained by the methanolic crude extraction (17.18±3.20%) while 9.60±2.14%, 2.80±0.59%, and 3.60±0.37% yields were from ethanol, acetone and chloroform extractions, respectively (p<0.05). DPPH scavenging activity of the methanolic and the ethanolic crude extractions were 21.47±2.81% and 14.93±2.55% (p<0.05). No malonaldehyde was produces in all seaweed extracts. A significantly less moisture loss was observed in seaweed coated fish samples compared to uncoated fish samples. Malondialdehyde produced in fish samples were significantly reduced with time. Consumer acceptance for 0.08 mg/mL seaweed concentrated fish sample was significantly different (p<0.05). This study concludes the preSence of bioactive components in crude exacts of S. ilicifolium and gelatine-based films and coatings made up of ethanolic extract of seaweed can be used as an ingredient of food industry.