This study aimed to optimize the hot water extraction conditions of polysaccharides from sulfur-fumigated GR (SGCPs) and nonsulfur-fumigated GR (NGCPs). The research explored the effects of sulfur fumigation on the structure and antioxidant activity of GR polysaccharides.
The results showed that the optimal extraction conditions for SGCPs and NGCPs were 67°C for 31 min with a liquid-to-material ratio of 15 mL/g and 64°C for 32 min with a liquid-to-material ratio of 17 mL/g, respectively. Compared with NGCPs, SGCPs exhibited significantly reduced DPPH radical, hydroxyl radical, ABTS+ radical scavenging activity, and Fe2+ chelating ability. Moreover, both NGCPs and SGCPs offered significant protective effects against H2O2−induced oxidative damage in RAW264.7 cells, but the protective effect of SGCPs was significantly lower than that of NGCPs. NMR analyses revealed that the main chain connections of SGCP3 and NGCP3 were both →4)-