A new source of galactomannan isolated from Gleditsia caspica (Persian honey locust) seeds: Extraction and comprehensive characterization

Abstract

The dominant objective of this study was to extract and purify galactomannan from Gleditsia caspica seeds. In addition to chemical analysis and investigation of the basic physicochemical and functional properties of the extracted galactomannan, other tests have been performed to determine the structural and thermal properties. The FT-IR spectra authenticated availability of O–H, C–H, and C–O stretching vibrations in the galactomannan conformation. The extracted galactomannan had amorphous structure with very low crystallinity which was obtained from XRD analysis. The obtained DSC and TGA plots showed thermal events including one endothermic and one exothermic peak that are typical for natural polysaccharides. The H-NMR analysis of the extracted galactomannan demonstrated peaks at δ 4.901 and 4.705 ppm, which were affiliated with availability of H-1 (α) (α-galactopyranosyl) and H-2 (β) (β-mannopyranosyl). The images obtained from SEM confirmed that the galactomannan surface was relatively smooth and uniform. Novelty Impact Statement The galactomannan was extracted and purified from Gleditsia caspica seeds. Comprehensive characterization of obtained galactomannan authenticated its chance to be applied as thickeners or stabilizers in food formulations as a new source of plant-based hydrocolloid.