Comparison of the Effects of pH-Shifting, Acetic Acid Modification, and TGase Treatment on the Physicochemical and Functional Properties of Wheat Gluten Protein

Wheat gluten protein (WGP) is a fine-quality plant-based protein resource. However, as its unparalleled reticulation structure, the processing properties of WGP are extremely poor, limiting its application. To overcome these drawbacks, the purpose of this work was to embellish wheat gluten protein by three relatively novel and mainstream chemical modifications. The results showed the pH-shifting treatment altered the apparent morphology of protein, showing a uniform flocculent structure, leading to significant improvements in foaming capacity and emulsification property. After deamidation by acetic acid, the solubility of WGP was greatly improved (60.1%), which was nearly four times that of the control group (15.8%), and its foam stability was also significantly improved. The WGP had the highest thermal stability (deformation temperature up to 148 ℃) after TGase deamidation. These results indicate that the three modification methods enhance the functional characters of WGP in different aspects and expand its application potential.