Effect of high hydrostatic pressure treatment on the structure and physicochemical properties of millet gliadin

The main purpose of this study was to investigate the effects of HHP pressure on the structure and physicochemical properties of millet gliadin. The effects of HHP pressure on its physicochemical properties, structure, and conformation were systematically studied by ultraviolet second derivative spectroscopy, fluorescence spectroscopy, Fourier transform infrared spectroscopy, and particle size analysis. HHP pressure treatment changed the spatial conformation of millet gliadin and increased the hydrophilicity of gliadin, but it did not alter the distribution of subunits. HHP pressure treatment changed the surface charge distribution of protein and increased the aggregation degree of protein, leading to the increase in protein particle size. After treatment, the α-helices and random coil ratio of the protein decreased, and some disulfide bonds formed, which made the protein structure more orderly and led to an increase in denaturation temperature. This phenomenon helped improve the limitation that millet gliadin cannot be directly used in the field of food production due to its strong hydrophobicity.