Structural and digestive characters of a heteropolysaccharide fraction from tea (Camellia sinensis L.) flower

Tea (Camellia sinensis L.) flower polysaccharides (TFPS) have various health-promoting functions. In the present work, the structure of a purified TFPS fraction, namely TFPS-1-3p, and its in vitro digestive properties were investigated. The results demonstrated that TFPS-1-3p was a typical heteropolysaccharide consisting of rham-nose (Rha), arabinose (Ara), galactose (Gal) and galacturonic acid (GalA) with a molecular weight of 47.77 kDa. The backbone of TFPS-1-3p contained -> 4)-alpha-D-GalpA(-6-OMe)-(1 -> 4)-alpha-GalpA-(1 -> and -> 4)-alpha-D-GalpA(-6-OMe)-(1 -> 2,4)-alpha-L-Rhap-(1 -> linkages. The branch linkages in TFPS-1-3p contained -> 6)-beta-D-Galp-(1 ->, -> 3,6)-beta-D-Galp-(1 ->, -> 5)-alpha-L-Araf-(1 -> and -> 3,5)-alpha-L-Araf-(1 ->. Subsequently, TFPS-1-3p could not be degraded under simulated human gastrointestinal conditions but could be of use to human fecal microbes, thereby lowering the pH and increasing the production of short-chain fatty acids (SCFAs) of the gut microenvironment and altering the composition of the gut microbiota. The relative abundance of Fusobacterium_mortiferum Mega-sphaera_elsdenii_DSM_20460, Bacteroides thetaiotaomicron, Bacteroides plebeius and Collinsella aerofaciens increased significantly, potentially contributing to the degradation of TFPS-1-3p.