Production of exopolysaccharide from probiotic Saccharomyces cerevisiae var. boulardii S11 and determination of its structural, rheological, antioxidant and prebiotic properties

This study is the first to report the production, characterization, and technofunctional properties of exopolysaccharide (EPS) from the probiotic yeast S. boulardii S11 (Sb-EPS). HPLC analysis revealed that Sb-EPS has a heteropolysaccharide structure composed mainly of mannose and glucose. FT-IR and NMR analyses confirmed the polysaccharide structure of EPS. Rheological analysis showed that Sb-EPS exhibited non-Newtonian shear-thinning flow behavior. The EPS exhibited high antioxidant activity at a concentration of 4 mg/mL, with more than 50% radical scavenging capacity for DPPH and ABTS, and 117.72 ± 2.54 mg/mL for FRAP. Additionally, Sb-EPS demonstrated 90.11, 71.30, and 55.95% heavy metal adsorption capacities for Cu²⁺, Fe²⁺, and Zn²⁺, respectively. Furthermore, Sb-EPS’s ability to stimulate the growth of probiotic bacteria L. rhamnosus and L. plantarum to a greater extent than glucose and inulin suggests its potential as a prebiotic candidate. The findings indicate that Sb-EPS could be a promising, novel, and functional ingredient for food applications.