Galactomannan esters - A simple, cost-effective method of preparation and characterization

Acetate, succinate and octenylsuccinate derivatives of galactomannans were prepared in anhydrous reaction conditions carried out at slightly elevated temperature (40-60 degrees C) using solid NaHCO3 as a mild base catalyst. Prior surface wetting of the reactants with similar to 5% absolute ethyl alcohol gave derivatives with a higher degree of substitution, although it decreased the slurry viscosity. Use of NaHCO3 significantly minimized high pH-induced degradative reactions, and its quantitative removal later was easily accomplished by repeated washings with aqueous ethyl alcohol. FT-IR, C-13-NMR, HPSEC and SEM data provided additional structural information. These derivatives are useful as functional food ingredients. (c) 2006 Elsevier Ltd. All rights reserved.