Octenyl succinylation of myofibrillar protein: Structural, physicochemical and emulsifying properties

In this study, different succinylation degree octenyl succinic anhydride modified myofibrillar protein (OSA-modified MP) were prepared through succinylation modification by adding various OSA (1%, 3%, 6%, 11%, 16%, 21% and 26% of the weight of MP) to MP. The structure, physicochemical properties and emulsifying properties of OSA-modified MP were investigated. Results showed that succinylation degree of the modified protein rose from 1.46% to 94.99%. Electrophoresis, fourier transform infrared spectroscopy, intrinsic tryptophan fluorescence emission spectroscopy and scanning electron microscopy demonstrated the structure of MP was changed. As the DS increased, the particle size decreased by the maximum values of 0.24 times, the surface net charge and solubility increased by the minimum values of 2.71 and 13.50 time, respectively. All these results caused emulsifying activity and emulsifying stability to increase by 2.32 and 1.46 times, respectively, indicated that succinylation greatly improved the emulsifying properties of MP. Compared to the native MP, OSA-modified MP was more beneficial to stabilize Pickering emulsion. Thus, succinylation improved the emulsifying properties of MP and effectively expanded the application range of MP in the food industry.