CHARACTERISATION, FRACTIONATION AND EMULSIFICATION PROPERTIES OF ACACIA POLYACANTHA GUMS

摘要

Acacia polyacantha was fractionated by a successive non-solvent fractionation technique, using ethanol and acetone separately as fractionating solvent. Four different fractions were obtained and labelled PO-E1F - PO-E4F and PO-A1F - PO-A4F in ethanol and acetone respectively. The whole gum and the fractions were fully characterised to determine the moisture, ash, pH, molecular weight, number average molecular weight, nitrogen content, intrinsic viscosity, emulsification performance and stability. The results for the fractions in both solvents showed lower moisture content, optical rotation and intrinsic viscosity while the uronic acid content was higher in all fractions apart from PO-A3F. The protein distribution associated with the high molecular weight fraction varied according to the fractionation step and solvent. The highest molecular weight was obtained for PO-E4F while the remaining fractions showed lower molecular weight compared to the control. All acetone fractions gave higher molecular weight compared to the control. The emulsification performance and stability was largely dependent on the protein distribution and its association with the higher molecular weight fractions. PO-E3F and PO-A4F gave better emulsification performance and stability than the control. PO-A4F gave results comparable to A. Senegal.