Effects of Succinylation on the Physicochemical Properties and Structural Characteristics of Edible Rapeseed Protein Isolate Films.

This study described the manufacture and characterization of different levels of succinic anhydride (0–15%, w/w) on rapeseed protein isolate (RPI) films. Mechanical, barrier, optical, surface, microstructure, and thermal properties were investigated. Results showed that 5% succinylated rapeseed protein isolate (SRPI) film revealed the overall optimal properties. The mechanical and barrier properties of 5% SRPI film were enhanced significantly compared to the RPI film. The water vapor permeability values of RPI and 5% SRPI films were 0.77 and 0.32 g mm/[hour m2 kPa], respectively. Succinylation improved the color of RPI. The contact angle of 5% SRPI film was 108.68° and was the most hydrophobic combination. Moreover, scanning electron microscopy images revealed that 5% SRPI showed a dense, homogenous, and smooth microstructure. Thermogravimetric analysis results verified a low level of succinylation strengthened the thermal resistance of SRPI films. The content of β‐sheet was almost half of all secondary structures after succinylation, which was supported by analyses of Fourier transform infrared spectroscopy. Results demonstrated that succinylation could be employed to improve the properties of rapeseed protein and SRPI films have great potential to be used as edible films. [ABSTRACT FROM AUTHOR]