Rheological Properties and Emulsion Stability of Peach Gum Polysaccharides with Different Molecular Weights

Peach gum polysaccharide (PGP), a natural biopolymer extracted from the resin of the peach tree, holds significant potential for applications in food, cosmetics, and pharmaceutical industries. However, detailed analysis and exploration of its physical and chemical properties remain limited. This study investigates the physicochemical properties, rheological behavior and emulsion stability of PGPs extracted using thermal (TPGP) and enzymatic (EPGP) methods. The results indicate that both polysaccharide fractions exhibit similar arabinogalactan (AG) structures, with high contents of arabinose and xylose, as evidenced by FTIR spectra and monosaccharide composition. However, high-performance size-exclusion chromatography (HPSEC) revealed differences in molecular weights and chain conformations, leading to distinct rheological behaviors. PGP solutions exhibited pseudoplastic flow behavior, with TPGP demonstrating higher viscosity due to its larger molecular weight (1.295 × 107 g mol−1). As the PGP concentration increased, gel strength and emulsion stability improved significantly. This study provides more insight into the rheological and emulsifying characteristics of PGPs extracted by varied methods, facilitating their potential applications in food industries.