Emulsification Properties and Molecular Weight Distribution of Combretum Glutinosum Gum

Abstract

The determination of weight average molecular weight (Mw) and radius of gyration (Rg) of Habeil gum was performed on a gel permeation chromatography-multi angle laser light scattering (GPC-MALLS) system. The results showed three main components of Combretum glutinosum gum designated arabinogalactan protein (AGP), arabinogalactan (AG) and glycoprotein (GP). The Mw of the freeze dried soluble part, freeze dried deacetylated gum, and freeze dried calcium-free gum were 2.06×10 6 , 8.03×10 5 , and 1.40×10 6 g /mol, respectively. The Mw of hydrophilic and hydrophobic components collected from soluble part gum are 3.16×10 6 and 6.08×10 5 g /mol, respectively, while the Mw of hydrophilic and hydrophobic components collected from deacetylated gum are 1.39×10 6 and 8.36×10 5 g /mol, respectively. Emulsification studies of the gum fractions showed lowest degree of span value than the starting material indicating good uniformity and increasing in adsorption of protein on oil droplet surface. The results of emulsion studies indicated that a blend of 50% w/w deacetylated Combretum glutinosum gum and 50% w/w Acacia Senegal produced better emulsification properties than the pure mother gum.