Abstract:

In this study, the effect of acidic and alkaline treatments on the monosaccharide composition, apparent viscosity and granularity on a polysaccharide fraction (detected to contain a single component) purified from Plantago asiatica L. seeds. Meanwhile, the thermal stability of the polysaccharide fraction was analyzed using thermal gravity-differential thrermal analysis (TG-DTA). The results showed that acidic and alkaline treatments both had certain effect on the apparent viscosity and monosaccharide composition of the polysaccharide fraction. After acidic treatment (approximately pH 2.7), the apparent viscosity and average granularity diameter of the polysaccharide fraction both increased, but the xylose/arabinose molar ratio changed little. However, alkaline treatment (approximately pH 11.4) resulted in a decrease in apparent viscosity, average granularity diameter and xylose/arabinose molar ratio. Heating followed by cooling resulted in an increase in average granularity diameter. The TG-DSC analysis showed that the polysaccharide fraction began to degrade at 250 ℃ and the degradation ended at 550 ℃.

Key words: Plantago asiatica L. seeds, polysaccharide, stability