Evaluation of selective extraction methods for recovery of polyphenols from pine (original) (raw)
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Isolation of pure pinosylvins from industrial knotwood residue with non-chlorinated solvents
Holzforschung
The aim of the study was to find appropriate non-chlorinated solvent systems for the extraction and separation of pure pinosylvin (PS) and pinosylvin monomethylether (PSMME) from Scots pine/Norway spruce wood residues. The extraction was performed in a pressurized solvent extractor and the purification and isolation of pure substances was done by flash chromatography. More precisely, pure PS was isolated via sequential flash chromatography in two repetitions in the gradient mode of the mobile phase, with cylcohexane (CX) and ethylacetate (EtOAc), beginning with 100% CX and ending up with 100% EtOAc. The extractives were qualitatively and quantitatively analyzed in terms of PS and PSMME contents by gas chromatography-flame ionization detector (GC-FID), gas chromatography-mass spectrometry (GC-MS), high-performance liquid chromatography (HPLC) and proton nuclear magnetic resonance (1H-NMR) spectroscopy.
Chemical Engineering Transactions, 2018
Pine bark extracts are a rich source of natural polyphenols with potential beneficial antioxidant properties. The extraction yield, antioxidant activity, as well the type of polyphenols recovered not only depend on the extraction method but also on the solvent used for extraction. Thus, the aim of the present study was to ascertain the effect of different solvents on extraction yield, total phenolic content and antioxidant activity of extracts from Pinus pinaster subsp. atlantica, the major forest biomass of Northwest of Portugal. Soxhlet extractions with water, water/ethanol (1/1) and just ethanol, as solvents, were performed for 4 hours. Best results were obtained with the water/ethanol mixture. Overall, the solvent's performance was as follows: water/ethanol> ethanol> water.
Forests
The aim of the study was to quantify total extractive contents and lipophilic compounds, stilbenes, and lignans in Scots pine stem wood, stem bark, branch biomass, and sawmill residues in four climatic regions of Finland to evaluate the most optimal sources of extractives for bio-based chemical biorefining and bioenergy products. Data were derived from 78 chip samples from the before-mentioned raw materials, the samples being pooled by tree height position from the sample trees of 42 experimental forest stands, and sawdust lots from 10 log stands. Accelerated solvent extraction (ASE) was employed to determine total extractive contents, followed by gas chromatography with flame ionization detection (GC–FID) to quantify extractive groups and gas chromatography-mass spectrometry (GC–MS) to analyse individual extractive compounds. Resin acids and triglycerides followed by fatty acids were the dominant extractive groups. Resin acids were most abundant in stem wood from final fellings and...
Chemical Product and Process Modeling, 2011
The bark extracts of various commercially important trees contain polyphenolics, which in the form of tannins can form condensation products with formaldehyde to produce wood adhesives. In the present work, aqueous acetone and aqueous ethanol were used as solvents to extract tannin from Pinus caribaea bark. The Stiasny number was determined as well as the amount of sugar co-extracted. Batch experiments were performed at different extraction times (30-180 min), extraction temperature (35-60°C for aqueous acetone; 35-80°C for aqueous ethanol), solvent concentration (10-100 percent), stage extraction (1-6) and liquid-solid ratio (10-50). A mathematical model was proposed to identify the effects of the individual interactions of these variables on the extraction of tannin using the two different solvents. The results have been modeled using response surface methodology. The response surface method was developed using five levels (-2, -1, 0, +1, +2) with the above mentioned factors excep...
Journal of Chromatography A, 2006
A method for quantitative determination of extractives from heartwood of Scots pine (Pinus sylvestris L.) using gas chromatography (GC) with flame ionization detection (FID) was developed. The limit of detection (LOD) was 0.03 mg/g wood and the linear range (r = 0.9994) was up to 10 mg/g with accuracy within ±10% and precision of 18% relative standard deviation. The identification of the extractives was performed using gas chromatography combined with mass spectrometry (GC-MS). The yields of extraction by Soxhlet were tested for solid wood, small particles and fine powder. Small particles were chosen for further analysis. This treatment gave good yields of the most important extractives: pinosylvin, pinosylvin monomethyl ether, resin acids and free fatty acids. The method is used to demonstrate the variation of these extractives across stems and differences in north-south direction.
The Journal of Supercritical Fluids, 2013
Highlights Pinus pinaster wood samples were extracted with near and supercritical CO2 The effect of pressure (10-25 MPa), temperature (30-50 °C) and ethanol as co-solvent was assessed Under selected conditions (25 MPa, 50 °C, 10% ethanol), 4 wt% was extracted One gram of extract contained 76 mg of GAE and was equivalent to 0.3 g Trolox Selected extracts contained 30% resin acids and 10% of the sum of flavonoids, lignans, stilbenes and juvabiones.
Forests
This study aimed to identify and quantify phenolic and resin acid extractive compounds in Scots pine stemwood and sawmill residues in four climatic regions of Finland to evaluate their most optimal sources for bio-based chemical biorefining and bioenergy products. The sample consisted of 140 trees from 28 stands, and sawdust lots from 11 log stands. NMR for the overall extractive analysis and HPLC for the quantitative estimation of phenolic and resin acid compounds were employed. Correlation analysis, multivariate factor analysis, principle component analysis and multiple linear regression modelling were applied for statistical analysis. HPLC identified 12 extractive compounds and NMR five more resin acids. Pinosylvin (PS), pinosylvin monomethyl ether (PSMME), and partly neolignans/lignans occurred in the largest concentrations. Wood type caused the most variation, heartwood having larger concentrations than sapwood (sawdust between them). Regional differences in the concentrations ...
Temperature and solvent effects on polyphenol extraction process from chestnut tree wood
Chemical Engineering Research and Design, 2011
Tannins are natural water-soluble products, characterized by a phenolic structure and the ability to bind and precipitate proteins. They are widely found in natural products, and their 'historical' utilization was in tanning animal hides into leather. Nowadays, tannins are extensively used in the food and beverage industry and in pharmaceutical and nutraceutical industries for their positive effects on human health. In conventional processes, tannins are extracted from vegetable material by using water as a solvent in a temperature range of 40-90 • C; other polyphenols are always extracted and classified as nontannins. The scope of this work is to characterize chestnut tree wood in terms of the total extractable tannins. To this aim, analytic methods, reported in the literature, for the quantitative determination of these compounds in aqueous solution of unknown composition have been assessed. Experimental data on equilibrium distribution of tannins between solid (wood) and liquid (water) at a temperature of 80 • C are presented. The obtained results have been correlated by means of the Freundlich isotherm. Experimental data are also reported on the extraction kinetics of tannins from the solid phase. Experimental extraction curves were simulated by a plug flow model, and an overall mass transfer coefficient was evaluated.
Pinus radiata barks obtained from tress of different ages, as subproduct of pulp and paper (trees less than 10 years) and sawmill (trees between 20 to 25 years) industries, were used to produce extracts containing phenolic compounds. A factorial design 2 3 was used to evaluate the influence of the variables temperature (25 -35 ºC), solvent type (acetone -ethanol) and extraction time (1-12 h). The extracts were compared in their extraction yield (%), total phenols (by FolinCiocalteau), and radical scavenging activity (by DPPH). The extract obtained from old trunks presented a higher extraction yield than from young trees. The highest yield value was 2.56%, which was obtained using acetone as solvent for 12 h and 35°C. The highest concentration of phenol (5.84±0.18 g CE g extract -1 ), and scavenging activity (IP=86.1±4.4%) were also obtained for this type of extract. The extraction duration was the variable that most influenced the parameters studied. The bark's radical scavenging power was greater than BHT (40%) and slightly lower than ascorbic acid (92%), common commercial antioxidants.
Wood Extractives in Conifers - A Study of Stemwood and Knots of Industrially Important Species
2018
Study of lipophilic and hydrophilic extractives in heartwood, sapwood and knots of 39 industrially important conifer species: 14 pines (Pinus), 7 spruces (Picea), 9 firs (Abies), 5 larches (Larix), 3 hemlocks (Tsuga) and Douglas-fir (Pseudotsuga). The wood samples were sequentially extracted, and the amount and composition of resin acids, fatty acids, sterols, steryl esters, acylglycerols, juvabiones, lignans, oligolignans, flavonoids and stilbenes were analysed by gas chromatography (GC) and GC-mass spectrometry.