Optimisation of pressurised liquid extraction for the determination of monosaccharides and polyalcohols in woods used in wine aging

Abstract

BACKGROUND: The carbohydrate profile of woods used to age wines and spirits is largely unstudied in spite of its possible influence on the quality of aged beverages. This experiment evaluated the feasibility of employing pressurised liquid extraction to isolate monosaccharides and polyalcohols from woods used in aging, yielding a reliable analytical extraction method for characterising these compounds. Various solvents were tested and the extraction procedure was optimised by a three-level factorial experimental design based on two main factors: extraction temperature and extraction time. The total extraction yield of target compounds was taken as response variable, and model parameters were estimated by multiple linear regression.

Derivatization of carbohydrates for GC and GC–MS analyses

“…A single peak is obtained for any non-reducing carbohydrate present (which do not form oximes). These derivatives are applicable to both aldoses and ketoses and have been widely used for carbohydrate determinations of complex mixtures, as they present good GC properties and provide simple chromatograms [15][16][17][18][19][20][21][22]. The samples are generally dissolved in pyridine containing 2.5% hydroxylamine hydrochloride and the solution is heated for 30 min at 75 • C. Then, for the silylation step, HMDS and TFA are added and the mixture is allowed to react for further 30 min at 45 • C [23,24].…”

Determination of carbohydrates in tobacco by pressurized liquid extraction combined with a novel ultrasound-assisted dispersive liquid–liquid microextraction method

“…PLE can generally operate under high pressure and temperature to efficiently extract carbohydrates from different matrix, providing faster extractions, lower solvent consumption, and higher extraction efficiency [14][15][16][17]. Ultrasonic assisted-dispersive liquid-liquid microextraction (UA-DLLME) is another new extraction and enrichment technique for using very low volumes of organic solvent [18][19][20].…”

Monosaccharide anhydrides, new markers of toasted oak wood used for ageing wines and distillates

“…Two compounds, whose identifications have not been possible, were also found and assigned as deoxyinositols due to the similarity of the mass spectra to that of quercitol. The presence of these unknown compounds has already been detected in other oak wood samples and published in a previous paper (Alañón et al, 2009). Muco-inositol, chiro-inositol, scyllo-inositol and myo-inositol were also found in the samples.…”

“…Extractions were performed using the optimized method developed in a previous study by our group (Alañón, Ruiz-Matute, Martínez-Castro, Díaz-Maroto, & Pérez-Coello, 2009). Three hundred milligram of sawdust mixed with two grams of diatomaceous earth as a dispersant agent, were placed in inox extraction cells of 11 ml.…”