Oil extracted from spent coffee grounds as a renewable source for fatty acid methyl ester manufacturing

Optimization and modeling of extraction of solid coconut waste oil

Purpose: To evaluate the in vitro cytotoxic, antioxidant and antimicrobial activities of Clinacanthus nutans extracts and semi-fractions. Method: The plant was subjected to cold solvent extraction to produce petroleum ether, ethyl acetate and methanol crude extracts, followed by isolation using bioassay-guided fractionation. The crude extracts (0.2 to 10.0 mg/ml) were tested against HeLa and K-562 cell lines using 3-(4,5-dimethylthiazol2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and antioxidant activity using 1, 1-diphenyl-2picrylhydrazyl (DPPH) assay. Furthermore, fractions isolated from ethyl acetate leaf extract (0.02 to 10.0 mg/ml) were tested against Bacillus cereus (ATCC11778), Escherichia coli (ATCC25922), Salmonella enterica Typhimurium (ATCC14028) and Candida albicans (ATCC10231) using minimum inhibitory concentration (MIC) and minimum bactericidal or fungicidal (MBC/MFC) assays. Results: Petroleum ether extracts demonstrated the strongest cytotoxic activity against HeLa and K562 cells with IC50 of 18.0 and 20.0 µg/mL, respectively. Petroleum ether extracts also displayed the highest radical scavenging activity of 82.00 ± 0.02 %, compared with ascorbic acid and α-tocopherol corresponding values of 88.7 ± 0.0 and 86.6 ± 0.0 %, respectively. In MIC assay, all the crude extracts and fractions showed inhibition against all tested microorganisms. Fraction 7 displayed the lowest MIC and MBC/MFC values against B. cereus and C. albicans at 1.39 mg/ml, respectively. Ampicillin and amphotericin B displayed MIC value of 1.3 mg/ml. Conclusion: The bioactive compounds from C. nutans are potential cytotoxic, antimicrobial and antioxidant agents.

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In Vitro Screening of Cytotoxic, Antimicrobial and Antioxidant Activities of Clinacanthus nutans (Acanthaceae) leaf extracts

In this study, the extraction of crambe seed oil Crambe abyssinica H. FMS Brilhante using subcritical propane as a solvent was investigated. The extraction yield and oil characteristics were compared with the oil extracted using n -hexane and dichloromethane. A factorial experimental design was used in order to evaluate the effects of temperature (313–353 K) and pressure (8–16 MPa) on the extracted yield using subcritical propane. It was observed that the temperature has the most significant effect on the extraction yield and the highest yield (32.8 wt%) was obtained at 353 K and 16 MPa. The experimental conditions showed no significant influence on fatty acids composition. Low levels of free fatty acids were found in the extracts (

Extraction of crambe seed oil using subcritical propane: Kinetics, characterization and modeling

Extraction of oil from Terminalia catappa L.: process parameter impacts, kinetics, and thermodynamics.

The physical and chemical indices of African breadfruit (Treculia Africana) seed oil extracted with polar (isopropanol, Hexane and butanol) and non polar (Acetone) solvents were investigated. The oil (19.85%) and energy contents 452.35 (Kcal) suggest that African breadfruit seeds are a high-energy food. The yields were significantly (P ≤ 0.05) different with hexane extracted (non-polar solvent) oil having 19.85% whilst oil extracted with polar solvents ranged from 15.58 -19.30%. Melting points were 34, 27, 26, 21 I¦C for oil extracted with hexane, isopropanol, butanol and acetone respectively. Smoke points were within the limits of 170 – 255  I¦C for the four oil samples. Iodine values ranged from 14.50 (hexane extracted) t0 25.17 (acetone extracted). Saponification values ranged from 125.89-267.85 while peroxide values were 3.20 mg/kg (hexane) and 3.60-3.83 mg/kg for polar solvents. Free fatty (oleic) acid of oil extracted with hexane was 1.71% and polar solvent extraction ranged from 1.65-1.78%. Hexane had the least peroxide value (8.74 mg/kg) compared to higher values for oil extracted with the polar solvents (9.10 - 9.83 mg/kg).

	 

	Keywords: African breadfruit, Treculia Africana, oil extraction, saponification, fatty acids, peroxide value, thiobarbituric acid.

Kalu Sunday Okocha

Papers

Extraction performances of polar and non-polar solvents on the physical and chemical indices of African breadfruit (Treculia africana) seed oil