Structural characterization and fermentation properties of a novel coix seed polysaccharide (CSP-A) with prebiotic...

Coix seeds, with high nutritional values and health functions, widely grown in East and Southeast Asia, has been traditionally used as a healthy food and medicinal grain for more than 1000 years in China. This study aimed to characterize the structure of a novel polysaccharide from Coix seed (CSP-A) and investigate its digestion and fermentation properties by human gut microbiota.

CSP-A is a water-soluble neutral polysaccharide (molecular weight ~ 2498 kDa) containing glucose and mannose with pyran group and α-glycosidic bond, and mainly contained α-d-Glcp-(1 → and →6), and α-d-Glcp-(1 →) two monosaccharide residues. The main chain of CSP-A was composed of α-1,6-d-Glc, and with small amounts of linear α-1-d-Glcp as the side-chains. After 48 h fermentation, 87.77% of total carbohydrate was utilized by gut microbiota. Total short-chain fatty acids (SCFAs) in the hydrolysate of CSP-A reached 58.0 mg/mL, higher than in CSP or control.

A novel polysaccharide CSP-A was purified from coix seed. Compared to the CSP, the purified polysaccharide CSP-A showed higher utilization rate and better prebiotic activity. As well as promoting the growth of beneficial bacteria, CSP-A inhibits the growth of intestinal disorders. Therefore, CSP-A has potential to developed into prebiotic products. © 2025 Society of Chemical Industry.