Abstract: In order to improve the mechanical properties, water resistance and barrier properties of rice bran protein (RBP) film, glycosylated RBP (RBP-G) film and RBP-G-chitosan composite (RBP-G-CS) film were prepared. The effects of the mass ratio of glucose to RBP and the mass ratio of RBP-G to chitosan on the mechanical properties of the films were investigated. The color, transparency, water resistance, water vapor permeability and thermal characteristics of RBP, RBP-G and RBP-G-CS films prepared under the optimal conditions were compared and analyzed. The structure of the films was characterized by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. The results showed that the mechanical properties of RBP-G film with a glucose to RBP ratio of 1:1 were obviously improved, and the tensile strength increased by 28.00% and the elongation at break by 33.13% compared with RBP film. RBP-G-CS film with a RBP-G to chitosan ratio of 1:1 had better mechanical properties, and its tensile strength and elongation at break increased by 197.33% and 84.42% compared with RBP film, respectively. The transparency, water resistance, barrier properties and thermal properties of RBP-G-CS film were significantly improved (P < 0.05). The structure of RBP-G-CS film was uniform and compact, owing to the strong hydrogen bonding forces. These results show that glycosylation modification can improve the performance of RBP film, and a good combination of modified RBP and chitosan can greatly improve the mechanical properties and water resistance of the film.

Key words: rice bran protein; chitosan; glucose; glycosylation; composite film