Suchergebnisse

Camellia (genus of flowering plants of fam. Theaceae) is one of the main crops in Asia, where tea and oil from leaves and seeds have been utilized for thousands of years. This plant is excellently adapted to the climate and soil of Galicia (northwestern Spain) and northern Portugal where it is grown not only as an ornamental plant, but to be evaluated as a source of bioactive compounds. In this work, the main fatty acids were extracted from Camellia seeds of four varieties of Camellia: sasanqua, reticulata, japonica and sinensis, by means of matrix-solid phase dispersion (MSPD), and analyzed by gas chromatography (GC) with MS detection of the corresponding methyl esters. MSPD constitutes an efficient and greener alternative to conventional extraction techniques, moreover if it is combined with the use of green solvents such as limonene. The optimization of the MSPD extraction procedure has been conducted using a multivariate approach based on strategies of experimental design, which enabled the simultaneous evaluation of the factors influencing the extraction efficiency as well as interactions between factors. The optimized method was applied to characterize the fatty acids profiles of four Camellia varieties seeds, allowing us to compare their fatty acid composition ; This research was supported by European Regional Development Fund 2007–2013 (FEDER), and project GPC2014/035 (Consolidated Research Groups Program of Galician Government Xunta de Galicia) ; SI

Grape seeds represent a high percentage (20% to 26%) of the grape marc obtained as a byproduct from white winemaking and keep a vast proportion of grape polyphenols. In this study, seeds obtained from 11 monovarietal white grape marcs cultivated in Northwestern Spain have been analyzed in order to characterize their polyphenolic content and antioxidant activity. Seeds of native (Albariño, Caiño, Godello, Loureiro, Torrontés, and Treixadura) and non-native (Chardonnay, Gewurtzträminer, Pinot blanc, Pinot gris, and Riesling) grape varieties have been considered. Low weight phenolics have been extracted by means of pressurized liquid extraction (PLE) and further analyzed by LC-MS/MS. The results showed that PLE extracts, whatever the grape variety of origin, contained large amounts of polyphenols and high antioxidant activity. Differences in the varietal polyphenolic profiles were found, so a selective exploitation of seeds might be possible ; This research was supported by European Regional Development Fund 2007-2013 (FEDER), and project GPC2014/035 (Consolidated Research Groups Program of Galician Government Xunta de Galicia) ; SI

In this study, green extraction methods—high voltage electrical discharges (HVED), pulsed electric field (PEF), and ultrasound-assisted extraction (UAE)—were compared in terms of extraction yield of total and individual polyphenolic compounds, as well as the antioxidant capacity of blueberry pomace extracts. All extractions were performed with methanol- and ethanol-based solvents. The highest total polyphenols content (TPC) (10.52 mg of gallic acid equivalent (GAE) per g of dry weight (dw)) and antioxidant activity (AA) (0.83 mmol TE/g dw) were obtained by PEF-assisted extraction in the ethanol-based solvent after 100 pulses and 20 kV/cm, which corresponds to an energy input of 41.03 kJ/kg. A total of eighteen individual polyphenols were identified in all investigated blueberry pomace extracts by high-performance liquid chromatography with the diode-array detector (HPLC-DAD) and liquid chromatography electrospray ionization tandem mass spectrometric (LC-(HESI)-MS/MS). The highest anthocyanin (1757.32 µg/g of dw) and flavanol (297.86 µg/g of dw) yields were obtained in the methanol-based solvent, while the highest phenolic acid (625.47 µg/g of dw) and flavonol (157.54 µg/g of dw) yields were obtained in the ethanol-based solvent by PEF-assisted extraction at the energy input of 41.03 kJ/kg. These results indicated that PEF is a promising green extraction method which can improve the blueberry pomace's polyphenol extraction yield ; This research was funded by the following projects: the "Atrium of Knowledge" project co-financed by the European Union from the European Regional Development Fund and the Operational Programme Competitiveness and Cohesion 2014–2020., Contract No:KK.01.1.1.02.0005, and by the project "Modification of cheese ripening process and development of whey based products—SIRENA" co-financed by the European Union from the European Structural and Investment Funds in the financial period 2014–2020 and the Operational Programme Competitiveness and Cohesion., Contract No:KK.01.1.1.04.0096. The ...

The sonochemical degradation of 5 μg l−1 triclosan, a priority micro-pollutant, in various environmental samples (seawater, urban runoff and influent domestic wastewater) as well as in model solutions (pure and saline water) was investigated. Experiments were conducted with a horn-type sonicator operating at 80 kHz frequency and a nominal applied power of 135 W, while solid-phase microextraction coupled with gas chromatography–electron capture detector (SPME/GC–ECD) was employed to monitor triclosan degradation. The latter followed pseudo-first order kinetics with the rate constant being (min−1): 0.2284 for seawater > 0.1051 for 3.5% NaCl in deionised water > 0.0597 for centrifuged urban runoff ∼ 0.0523 for untreated urban runoff > 0.0272 for deionised water > 0.0063 for wastewater influent. SPME/GC–ECD and SPME coupled with gas chromatography–mass spectrometry (SPME/GC–MS) were also used to check for the formation of chlorinated and other toxic by-products; at the conditions in question, the presence of such compounds was not confirmed ; L.S.-P. and R.B. acknowledge the regional government Junta de Galicia for their doctoral and travel grants ; SI