Vanillin-assisted preparation of chitosan-betaine stabilized corn starch gel: Gel properties and microstructure characteristics

Modification of starch to realize the value-added utilization of starch is a hot research topic at present. In this study, the complex composed of chitosan, betaine and vanillin with different concentrations was used as a new starch modifier to modify corn starch based on special mechanism, and the gelatinization, rheological, gel, thermal characteristics and structural characteristics of starch gel were evaluated. The gelatinization results showed that chitosan, betaine and vanillin complex can significantly increase the viscosity of starch including peak, breakdown, final and setback viscosity, which proved its potential as a gel thickener. The results of rheological properties showed that the viscoelasticity of corn starch was significantly increased after modification. The gel characteristics also presented that the modifier can promote the gel formation and can be used as gelling agent. The thermal stability of modified corn starch was also significantly improved. FT-IR and XRD results show that chitosan, betaine and vanillin can improve starch properties mainly through hydrogen bond interaction, Schiff base crosslinking and electrostatic interaction. Moreover, SEM showed the microstructure of corn starch became more orderly and regular with the addition of modifiers. The results show that the complex of chitosan, betaine and vanillin can be used as a new gel thickener and stabilizer in the industry, and has the potential for improvement. This will provide theoretical reference for expanding the application scope of starch and realizing the value-added utilization of starch.