Ultrasonic irradiation induces degradation and improves prebiotic properties of polysaccharide from seeds of Plantago asiatica L. during in vitro fermentation by human fecal microbiota

Influence of ultrasonic irradiation in the polysaccharide from the seeds of Plantago asiatica L. and its prebiotic properties during in vitro fermentation using human fecal microbiota were evaluated. Average particle size and molecular weight of the polysaccharide was declined due to ultrasonic irradiation. After ultrasonic irradiation, the amount of reducing sugar increased, which suggested that the polysaccharide degradation may result from the glycosidic bond rupture. The surface topography of polysaccharide was also altered from large flake-like lamella to smaller fragments. However, short-chain fatty acid productions during fermentation of polysaccharide increased significantly after being ultrasonic treated (p < 0.05). Population sizes of Lactobacillus and Bacteroidaceae in ultrasonic treated-polysaccharide fermentation cultures were also notably larger than that in untreated-polysaccharide fermentation culture (p < 0.05). These results revealed that ultrasonic irradiation could be a promising degradation method for producing value-added polysaccharide.