Preparation, properties and emulsifying capacity of octenyl succinic anhydride modified peach gum polysaccharide

In this study, octenyl succinic anhydride modified peach gum polysaccharide (OSPG) with different substitution rate (0.93 % to 2.02 %) were prepared and their properties were assessed. FTIR spectroscopy showed two new peaks for OSPG spectrum at 1726 cm^-1 and 1569 cm^-1, respectively. ¹H NMR showed that OSPG showed many octenyl succinic anhydride (OSA) characteristic peaks in the range of 0.7-3.0 ppm and 5.3-5.5 ppm. FTIR and ¹H NMR confirmed the success of grafting modification. The TG curves showed the thermal decomposition temperature of the OSPG was higher than peach gum polysaccharide (PGP) in the second stage. Compared with PGP, the particle size and the absolute value of the zeta potential of OSPG solutions also increased. The emulsifying activity of PGP increased from 30.67 % to 77 % after modification and the OSPG emulsion still showed good emulsifying stability after 3 months. The encapsulation efficiency of the curcumin emulsion was increasing from 69.49 % stabilized by of PGP to 80.99 % stabilized by OSPG. Overall, OSPGs with both hydrophilic and hydrophobic groups can serve as emulsifiers, exhibit excellent emulsion stability during prolonged storage periods, and can be utilized for encapsulating lipophilic bioactive substances.