Application of aqueous two phase systems based on polyethylene glycol and sodium citrate for the recovery of phenolic compounds from Eucalyptus wood

Lucía Xavier,Isabel Vidal-Tato,Julia González-Álvarez,María Sonia Freire

doi:10.4067/s0718-221x2015005000032

Lucía Xavier, Isabel Vidal-Tato + Show 2 more

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https://doi.org/10.4067/s0718-221x2015005000032

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Abstract

This paper proposes an alternative way to intensify the exploitation of Eucalyptus wood wastes before valorisation for energy production. An aqueous two-phase system (ATPS) based on PEG 2000 and sodium citrate was investigated for the recovery of phenolic compounds that could act as natural antioxidants for applications including cosmetics, pharmaceuticals, food additives and other industrial applications. The influence of the tie line length (TLL) (26,1-46,1%), extraction temperature (25-65oC), extraction time (90-390 min) and phase settlement time (1-8 h) were studied. Phenolic compounds were concentrated preferentially in the PEG-rich phase. A partition coefficient of 38 and a total phenols yield of 1,29 mg gallic acid equivalent/100 mg wood dry basis were obtained under the operational conditions selected: TLL, 46,1%, temperature 65oC, extraction time 90 min and settlement time 1 h. Analysis of the extracts by RP-HPLC-ESI-TOF confirmed the presence of various phenolic compounds with demonstrated antioxidant activity: monogalloyl glucose, (-)-gallic acid, ellagic acid and quercetin 3-O-rhamnoside.

Highlights

IntroductionMuch attention is being paid to the exploitation of biomass residues. Generally, these residues are burnt for power generation
As of late, much attention is being paid to the exploitation of biomass residues
The recovery of phenolic compounds from eucalyptus wood wastes using aqueous two-phase systems based on polyethylene glycol (PEG) 2000 and sodium citrate was studied

Summary

Introduction

Much attention is being paid to the exploitation of biomass residues. Generally, these residues are burnt for power generation. Extraction is a common method for the isolation of natural antioxidants and it is mainly performed with organic solvents (Vázquez et al 2008, Aspé and Fernández 2011, Fernández-Agulló et al 2013, Ramos et al 2013). This procedure is efficient and solvents such as ethanol are GRAS (generally recognized as safe), the extracts from other solvents are generally not safe for human consumption due to potentially toxic effects of residual solvents (Salic et al 2011).

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