Recovery of gallic acid with colloidal gas aphrons generated from a cationic surfactant

Spigno, G., Dermiki, M., Pastori, C., Casanova, F. and Jauregi, P. (2010) Recovery of gallic acid with colloidal gas aphrons generated from a cationic surfactant. Separation and Purification Technology, 71 (1). pp. 56-62. ISSN 1383-5866 doi: 10.1016/j.seppur.2009.11.002

Abstract/Summary

In a previous study we have demonstrated that gallic acid (GA) in its anionic form can be recovered from aqueous solutions using colloidal gas aphrons (CGA) generated from the cationic surfactant cetyltrimethylammonium bromide (CTAB). The aim of the present work is to get a better understanding of the separation mechanism in order to determine the optimum operating conditions to maximise the recovery of GA while preserving its antioxidant properties. Zeta potential measurements were carried out to characterise the surface charge of GA, CTAB and their mixtures at three different pH conditions (both in buffers and in aqueous solutions). GA interacted strongly with CTAB at pH higher than its pKa 3.14 where it is ionised and negatively charged. However, at pH higher than 7 GA becomes oxidised and loses its antioxidant power. GA recovery was mainly affected by pH, ionic strength, surfactant/GA molar ratio, mixing conditions and contact time. Scale-up of the separation using a flotation column resulted in both higher recovery and reproducibility. Preliminary experiments with grape marc extracts confirmed the potential application of this separation for the recovery of polyphenols from complex feedstocks

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/26093
Item Type	Article
Refereed	Yes
Divisions	Life Sciences > School of Chemistry, Food and Pharmacy > Department of Food and Nutritional Sciences > Food Research Group
Publisher	Elsevier
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