Study on the physicochemical and functional properties of glutinous rice protein modified by frozen ball milling

This study explored the influence of frozen ball milling on the physicochemical properties and functional characteristics of glutinous rice protein. After grinding glutinous rice protein at 0 minutes, 10 minutes, 20 minutes, 30 minutes and 40 minutes, physicochemical indexes showed that with the extension of milling time, the particle size of glutinous rice protein decreased significantly, the free sulfhydryl content increased first and then decreased, the surface hydrophobicity increased gradually, the α-helix content decreased first and then increased, the β-sheet content decreased gradually, and the secondary structure was transformed. However, the electrophoresis bands did not change obviously before and after frozen ball milling. Functional indexes showed that the solubility of glutinous rice protein increased first and then decreased after frozen ball milling. With the increase of the frozen ball milling time, the emulsification activity of glutinous rice protein tended to increase first and then decrease. The emulsifying stability of glutinous rice protein decreased after undergoing freezing and ball milling, showing a notable decrease from 21.25% before frozen ball milling to 8.42% after 40 minutes of ball milling. This indicates that frozen ball milling is an effective method for producing modified glutinous rice protein products with new structure and characteristics.