Physical properties and antidiabetic potential of a novel galactomannan from seeds of Gleditsia japonica var. delavayi

In this paper, the physical properties of a soluble non-starch polysaccharide (EGSP) from the endosperm of Gleditsia japonica var. delavayi seeds, and its effects on starch digestibility, glucose diffusion and glycemic index (GI) were investigated. EGSP has good acid-base and thermal stability and can form high viscosity solutions at low concentrations. Its real density (RD), solubility and lowest-gelled-concentration (LGC) are 1.33 ± 0.03 g/mL, 1.24 ± 0.15 g/100 mL and 20 g/L. Besides, EGSP also had certain oil and glucose adsorption properties. In vitro experiments showed that EGSP could effectively reduce the starch digestibility and glucose diffusion rate, which might be due to its high viscosity and the abilities of hindering starch gelation. Further in vivo experiments confirmed that EGSP can reduce the GI of starchy foods and inhibit the surge of postprandial blood glucose level.