In this study, carob gum (LBG) which is known to be partially soluble at ambient temperature, was fractionated using temperature of solubilisation (at 23°C, 37°C and 80°C). Two approaches were used. In the first approach, three successive fractions were obtained from one LBG sample starting by a solubilisation at 23°C, followed by a solubilisation at 37°C and finally at 80°C on the insoluble residues. In the second approach three different fractions were obtained from three LBG samples, using a simple fractionation at three different temperatures (at 23°C, at 37°C or at 80°C). The purified fractions obtained were investigated using GLC, SEC and Bolhin rheometer instruments, to gain a clearer picture of their chemical and physico-chemical feature. All the results show that the extracted galactomannan fractions, exhibit molecular characteristics (M/G ratio and intrinsic viscosity) and rheological properties which increase with the temperature of solubilisation/extraction. In addition, these fractions were more soluble at their specific temperature of solubilisation, gave more clearly solutions and higher viscosity than the crude gum. These fractions might be applied industrially as refined thickeners to confer desired properties to food and non-food products at a required temperature.
Keywords: Galactomannan, Locust Bean Gum, Macromolecular Data, Rheological Properties, Sugar Composition, Water-Soluble Polymer
