Artificial simulated saliva, gastric and intestinal digestion of polysaccharide from the seeds of Plantago asiatica L.

The saliva, gastric and intestinal digestion of polysaccharide from Plantago asiatica L. seeds was investigated in vitro. It was found that salivary amylase had no effect on the polysaccharide; however, the polysaccharide was influenced in later gastrointestinal digestion. A steady decrease in molecular weight (Mw) of the polysaccharide from 1903.1 ± 93.0 to 4.7 ± 0.2 kDa was observed as digestion time increased. Meanwhile, the reducing ends were increased from 0.157 ± 0.009 to 0.622 ± 0.026 mM, indicating the decrease of Mw may due to the breakdown of glycosidic bonds. In addition, there was no monosaccharide released throughout the whole digestion period, suggesting that the gastrointestinal digestion did not result in a production of free monosaccharide. These results may provide some information on the digestion of polysaccharide from P. asiatica L. in vitro, and may contribute to the methods of studying the digestion of other carbohydrates.