Changes in the Physicochemical Characteristics and Multi-Scale Structure of Starch–Gluten Dough: Effects of Oil Modification and Thermal–Mechanical Treatment

In this study, the influence of oil modification and thermal–mechanical treatment on the physicochemical characteristics and multi-scale structure of doughs prepared mainly with wheat starch and gluten was investigated. Oils with different structures reduced the hardness of model dough and improved the tensile strength. Oil modification also reduced starch–gluten dough disulfide bond, hydrogen bond, and hydrophobic interactions in starch–gluten dough, inhibited wheat starch retrogradation. The X-ray diffraction patterns of dough were characterised by new peaks at approximately 7.6°, 12.9°, and 19.8°, indicating that thermal–mechanical treatment promoted the formation of typical V-type complexes. Oil modification impaired dough short-range ordered structure, thereby preventing starch granule degradation caused by thermal–mechanical treatment. Scanning electron microscopy revealed that oil modification and thermal–mechanical treatment synergistically affected starch–gluten agglomeration. Our findings enabled us to elucidate the influence of oil modification and thermal–mechanical treatment on starch–gluten dough functionality.