Elucidation of the Emulsification Properties of Sugar Beet Pectin

Williams, Peter A; Sayers, C; Viebke, C; Senan, Chandra; Mazoyer, J and Poulenguer, P (2005) Elucidation of the Emulsification Properties of Sugar Beet Pectin.

View this record at http://dx.doi.org/10.1021/jf0404142

Abstract

A protocol has been developed to fractionate sugar beet pectin using hydrophobic affinity chromatography. Three samples eluted from the column using 4 M NaCl as solvent (fractions 1A, 1B, and 1C), two fractions eluted using 2 M NaCl (fractions 2A and 2B), and one fraction eluted using water (fraction 3). The fractions were shown to be very polydisperse, and differences between the GPC refractive index and UV absorbance (214 nm) elution profiles demonstrated chemical heterogeneity. They were found to contain significantly different proportions of protein (1A, 2.79%; 1B, 0.97%; 1C, 0.77%; 2A, 1.41%; 2B, 5.09%; and 3, 5.89%) and ferulic acid (approximately 1A, 0.5%; 1B, 0.5%; 1C, 0.9%; 2B, 1.5%; and 3, 2%). The weight-average molecular mass, Mw, of the fractions also varied (1A, 153 kDa; 1B, 155 kDa; 1C, 306 kDa; 2A, 562 kDa; 2B, 470 kDa; 3, 282 kDa). Three fractions, that is, 1A, 1B, and 3, produced orange oil emulsions with a relatively small droplet size that were stable over a period of weeks. The other three fractions (1C, 2A, and 2B with higher Mw values) produced emulsions with an initially larger droplet size, and the droplet size increased considerably over time. The increased droplet size may be influenced by the viscosity of the aqueous continuous phase. There was no simple relationship between protein or ferulic acid content and emulsification ability. For example, fraction 1B, which contained the lowest proportion of both protein and ferulic acid, produced stable emulsions of similar droplet size to fraction 3, which contained the largest proportion of protein and ferulic acid. The role of protein in the emulsification process was investigated by measuring the amount of protein in the aqueous phase before and after emulsification. It was clearly demonstrated that proteinaceous material adsorbed at the oil−water interface. It is evident that the emulsification properties of sugar beet pectin are influenced by the accessibility of the protein and ferulic acid groups to the surface of the oil droplets, the proportion of ester groups, and the molecular mass distribution of the fractions.

Item Type: Article
Additional Information: Copyright © 2005 American Chemical Society Metadata only available from this repository This article was originally published in the Journal of Agricultural and Food Chemistry in 2005 published by the American Chemical Society.The full article can be found at http://dx.doi.org/10.1021/jf0404142
Keywords: emulsification, Sugar beet pectin, molecular mass characterization, hydrophobic affinity chromatography, gel permeation chromatography, droplet size distribution
Members: Glyndŵr University
Depositing User: ULCC Admin
Date Deposited: 05 Oct 2011 09:14
Last Modified: 20 Mar 2016 21:19
URI: http://collections.crest.ac.uk/id/eprint/307

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