Structural characteristics and emulsifying properties of lotus seed protein isolate-dextran glycoconjugates induced by a dynamic high pressure microfluidization Maillard reaction

Lotus seed protein isolate (LSPI) is nutritious but with poor solubility and emulsifying properties. Therefore, to improve utilization of LSPI in the food industry, glycoconjugates with LSPI and Dextran under dynamic high pressure microfluidization (DHPM) assisted glycosylation reaction method were produced, which dramatically accelerated the glycosylation reaction and contributed to grafting more dextran on LSPI compared with traditional treatment. The formation of new peaks in a Fourier transform infrared spectrum and the increase of grafting degree were verified by the successful generation of LSPI-Dextran glycoconjugates. Secondary and tertiary structural results suggested that DHPM-induced glycosylation reaction promoted the unfolding of LSPI molecules with more flexible conformation. The solubility and emulsifying properties of LSPI-Dextran glycoconjugates were dramatically improved with an increase in treatment pressure. Moreover, confocal laser scanning analysis confirmed LSPI-Dextran glycoconjugate with the assistance of 120 MPa DHPM could produce the smallest and most homogeneous oil droplets. LUMiSizer centrifugal analysis observed the slowest transmission profiles, further confirming that 120 MPa DHPM optimal treatment for glycation reaction between LSPI and Dextran, which showed the greatest improvements in emulsifying ability and stability. These findings provided a foundation for the development of LSPI-based products with desirable characteristics.