Modifying oat protein by industry-scale microfluidization system combined with alcalase: Evaluation of rough texture,...

Due to low emulsification capacity and other reasons, the large-scale commercial application of oat protein (OP) was limited. In this study, the modification methods of industry-scale microfluidization (ISM), alcalase and combined treatments were used to enhance the emulsification and processing characteristics of OP. The structural changes after modification were also determined to explore the modification mechanism. The results showed that the particle size of OP was significantly reduced (P < 0.05), and the friction coefficient was reduced by 48.38 %, 16.28 %, and 41.47 % after ISM, alcalase, and co-modification, respectively. This means the texture became smoother. After modifications, the particle size and ζ-potential of the OP emulsion significantly decreased at high temperatures and pH 5.0 and 7.5 conditions (P < 0.05). The combined treatments has the strongest capacity. By observing the microstructure of OP before and after modification, it was clear that the three modification methods loosened the OP structure and reduced its particle size. The hydrolysis of alcalase and the strong shear force of ISM also changed the molecular weight, secondary structure, and tertiary structure of the OP. In addition, the α-helix/β-sheet ratio of the modified OP significantly increased from 0.74 to 1.07-1.51 (P < 0.05), which further affected the emulsification characteristics of OP. This study provided the idea and feasible scheme for the modification and high-value utilization of the OP.