An investigation of the mechanism of emulsion stabilization in octenyl succinic anhydride-modified tamarind seed polysaccharide

Previous studies have shown that octenyl succinic anhydride-modified tamarind seed polysaccharide (OTSP) is an effective emulsion stabilizer. In this study, the fine structure and interfacial behavior of OTSP were investigated using a variety of methods to elucidate its mechanism for stabilizing emulsions. First, the results of nuclear magnetic resonance indicated that the esterification reaction occurred at the 6th carbon atom of glucose, which was not replaced by xylose in the main chain of TSP. Then, the studies of the interfacial behavior showed that OTSP adsorbed more at the oil-water interface than TSP, and that the intermolecular interactions of OTSP were stronger than those of TSP. The adsorption of OTSP at the interface was dominated by diffusion. Compared to TSP, OTSP formed a denser and more flexible interfacial layer and was resistant to large deformations and highfrequency perturbation. Molecular dynamics simulations revealed the presence of an Omega-like structure in the OTSP molecule. This structure reduced the degree of ordering of its molecular chains, resulting in a more flexible and looser structure that facilitated the rearrangement of OTSP molecules at the interface. The hydrophobic groups anchored the OTSP to the surface of the oil droplets, fixing them in the network structure, further restricting droplet movement and thus improving emulsion stability. The results of this study contribute to the understanding of the mechanism of polysaccharide-stabilized emulsion, which is of great significance in promoting the application of TSP in the food industry.