Effect of Extrusion Temperature on the Structure of High-moisture Extruded Mung Bean Protein

In this paper, mung bean protein was prepared by high moisture extrusion technology at different extrusion temperatures. The structure of the protein was analyzed by Fourier transform infrared spectroscopy, internal fluorescence spectroscopy, SDS-PAGE gel electrophoresis, and scanning electron microscopy. The results showed that the content of ionic bond, hydrophobic interaction, and disulfide bond increased first and then decreased, and the content of free thiol decreased first and then increased, after high-moisture extrusion. The content of β-sheet in the secondary structure of protein decreased significantly (P<0.05), and the content of α-helix and β-turn increased significantly (P<0.05). The endogenous fluorescence spectra showed that the maximum emission wavelength of protein showed redshift at 130 and 140 ℃, while the maximum emission wavelength of protein did not change significantly at 150 and 160 ℃. The fiber structure of mung bean protein was observed by scanning electron microscope. In conclusion, the structure of mung bean protein after high moisture extrusion treatment would change, and extrusion temperature would have a significant effect on the high-moisture extrusion textured products of mung bean protein.