Methylene blue adsorption onto crosslinked sago starch

Crosslinked sago starch was prepared by crosslinking native sago starch with sodium trimetaphosphate (CSS-STMP) and epichlorohydrin (CSS-EPCH) as renewable adsorbents. CSS-STMP and CCS-EPCH were used to remove methylene blue (MB) from aqueous solution based on its characterization tests. The adsorption capacity of CSS-STMP and CSS-EPCH were evaluated as a function of pH, adsorbent dosage, initial MB concentration, contact time and temperature. It was favorable for adsorption under condition of pH 7 and at 50 ppm for both adsorbent. The adsorption capacity trend was reduced with increasing adsorbent dosage where 0.05 g dose of adsorbent was chosen. Equilibrium adsorption capacity (qe) of MB adsorption onto CSS-STMP and CSS-EPCH were 2.224 mg g-1 and 1.303 mg g-1, respectively. CSS-STMP adsorbent was employed for further experiment due to its better performance than CSS-EPCH. The equilibrium isotherms were conducted using Langmuir, Freundlich and Tempkin models. It has been demonstrated that a better agreement was Langmuir isotherm with a correlation coefficient (R2) of 0.990, complete monolayer adsorption capacity (qm) of 3.731 mg g-1, chi-square test (2) of 0.029% and corresponding contact time of 4 hours. The pseudo-first-order, pseudosecond- order and intra-particle diffusion were used to fit adsorption data in the kinetic studies. The results show that the adsorption kinetic was more accurately described by the pseudo-second-order model with the mechanism via film diffusion where R2 is 0.999 and variance is 0.152%. The adsorption of MB on CSS-STMP was exothermic and non-spontaneous in nature at temperature of 303K. Regeneration study also indicated that CSS-STMP adsorbent have the potential to be reused at the same adsorption performance for numbers of cycle. The obtained results suggest that CSS-STMP could be a promising candidate as an adsorbent for MB removal

Influence of Solvent Polarity and Conditions on Extraction of Antioxidant, Flavonoids and Phenolic Content from Averrhoa bilimbi

This paper presents the influence of solvent polarity and extraction conditions on the extraction of total flavonoid, total phenolic and antioxidants from Averrhoa bilimbi. The experiment was performed using a different solvent at different extraction conditions, including extraction time (15-240 min), temperature (30-70 °C) and agitation speed (50-300 rpm). Results showed that yields of extraction varies with solvent polarity. Extraction using 50% aqueous methanol gives the highest antioxidant activity and flavonoid content. The highest total flavonoid content (193.3 µg quercetin equivalent/g dry weight), total phenolic content (717.8 µg gallic acid equivalent/g dry weight) and antioxidant activity (77%) was achieved using 50% methanol, at 70 °C and agitation speed of 300 rpm. This work may be useful for obtaining higher bioactive compounds during the extraction process of A. bilimbi

Quantification of bioactive compounds from Averrhoa Bilimbi

Averrhoa bilimbi has been widely used in traditional medicine, thus, this fruits have received much attention because of its nutritional and antioxidant properties. The purposes of this study are to determine the bioactive compounds in averrhoa bilimbi and to study their optimum parameters during extraction. Antioxidant activity of the averrhoa bilimbi extract was determined based on 2,2-diphenyl-1-picrylhydrazyl freeradical (DPPH·), total phenolic content was measured using Folin–Ciocalteu reagent, while flavonoids is determined spectrophotometrically. Solvent extraction selected is methanol (50%) where this condition has yielded total flavonoids content is about 568.75 μg/ml QE. The highest antioxidant capacities measured is 80.02 % and total phenolic content shows about 175.3 mg/mL GAE.In this study, 60 minutes extraction time generally showed the highest effect on total flavonoids which is 496.25 μg/ml QE. Averrhoa bilimbi extraction had total phenolic about 164.7 mg/mL GAE and antioxidant activity is around 74.5%. 70° C extraction temperature shown the best extraction for total phenolics at 127.7 mg/ml GAE, while achieved highest total flavonoids at 656.25 μg/ml QE and the highest for DPPH radical scavenging activity is found about 70.05%. From the effect of agitation speed, 300 rpm achieved the highest value for total phenolics, total flavonoids and antioxidant capacity, DPPH which is about 193.3 mg/ml GAE, 717.75 μg/ml QE, and 77.03% respectively. Overall, based on the ideal extraction conditions chosen, optimum level of TPC, TFC and antioxidant capacity were obtained in averrhoa bilimbi fruit extract. The selected extraction conditions could be used for further studies and functional food product development

Influence of Solvent on Extraction of Antioxidant, Flavonoids and Phenolic Content from Averrhoa bilimbi

This paper presents the influence of solvent polarity and extraction conditions on the extraction of total flavonoid, total phenolic and antioxidants from Averrhoa bilimbi. The experiment was performed using a different solvent at different extraction conditions, including extraction time (15-240 min), temperature (30-70 °C) and agitation speed (50-300 rpm). Results showed that yields of extraction varies with solvent polarity. Extraction using 50% aqueous methanol gives the highest antioxidant activity and flavonoid content. The highest total flavonoid content (193.3 µg quercetin equivalent/g dry weight), total phenolic content (717.8 µg gallic acid equivalent/g dry weight) and antioxidant activity (77%) was achieved using 50% methanol, at 70 °C and agitation speed of 300 rpm. This work may be useful for obtaining higher bioactive compounds during the extraction process of A. bilimbi