Abstract:This paper investigated the influence of nano grinding on particle size，molecular weight，free sulfhydryl content，and endogenous fluorescence spectrum of whey protein concentrate（WPC）and whey protein concentrate micro-gel particles（WPM），as well as the effect of the changing protein multi-scale structure on the micro-rheological properties，storage stability，and microstructure of the emulsion stabilized by whey protein concentrate and WPM，to characterize the change rule of the interfacial properties of WPC.The results showed that nano grinding could significantly reduce the particle size of WPC and strengthen the concentration of particle size distribution.The molecular weight of proteins showed no significant variation after the nano grinding.However，the content of free sulfhydryl groups obviously decreased，indicating the formation of a large number of intramolecular disulfide bonds.According to the endogenous fluorescence spectra，the maximum absorption wavelength of WPC shifted from 333 nm to 339 nm，suggesting the exposure of embedded hydrophobic group and the enhancement of surface hydrophobicity.Compared with the other emulsions，the sWPM-8h emulsion had the strongest elasticity index and macroscopic viscosity index，the lower solid-liquid equilibrium value，the lowest fluidity index and the highest storage stability after nano grinding and microparticulation treatment.All the results indicated that nano grinding could improve the interface properties of whey protein concentrate.