Characterization of Peperomia leptostachya polysaccharides and functional properties of their Maillard reaction products with whey protein isolate.

Whey protein isolate (WPI) has excellent emulsifying properties but lacks antioxidant activity, limiting its effectiveness in oil-in-water emulsions. Modifying WPI via the Maillard reaction with polysaccharides may produce compounds with enhanced antioxidant properties while retaining their emulsifying ability. In this study, a novel polysaccharide, SCCP-1-1, was extracted from Peperomia leptostachya for the first time. Chemical analysis and NMR confirmed that SCCP-1-1 is a glucan composed of residues such as →3,6)-α-Glcp-(1→, α-Glcp-(1→, and 6)-α-Glcp-(1→, with a molecular weight of 37,458 Da. Thermogravimetric analysis and differential scanning calorimetry revealed that SCCP-1-1 remains thermally stable up to 200 °C. Its antioxidant capacity was also significant. The emulsifying and antioxidant properties of Maillard reaction products (SW-MRPs) derived from WPI and SCCP-1-1 were further investigated, revealing a marked improvement in antioxidant activity with minimal impact on the emulsifying properties of WPI. These findings underscore the potential of SCCP-1-1 in food and pharmaceutical applications.