Effects of extraction methods on structural characteristics and bile acid-binding capacities of Moringa oleifera leaf polysaccharide fractions

摘要

There is an urgent need for safe and effective bile acid sequestrants from edible plants to treat hyperlipi-daemia. Moringa oleifera leaf has been reported to be a source of hypolipidaemic agents. However, limited information is available on the bile acid-binding capacity of M. oleifera leaf polysaccharide fraction (MOLPF). To illustrate structure-bile acid-binding capacity relationship of MOLPFs obtained by eight common extraction methods and provide an extraction technique for MOLPF with strong bile acid-binding capacity, structure characteristics and bile acid-binding capacities of MOLPFs were investigated. The results indicated that extraction method greatly affected morphology, monosaccharide composition, glycosidic linkage and molecular weight distribution of MOLPF. MOLPFs with lower contents of galactose and more branched components exhibited lower binding rates. MOLPFs prepared by cellulase and ultrasonic-assisted cellulase extraction methods possessing the highest contents of galactose and relatively high proportions of linear macromolecules exhibited the strongest binding capacities, showing potential hypolipidaemic effects.