Effect of oleic acid-rich rapeseed oil on the physicochemical, rheological, and structural characteristics of wheat dough

Some wheat-based foods require different doses of oil to moderate quality of dough during processing and the influence mechanisms remain unclear. Therefore, the effect of rapeseed oil addition on physicochemical characteristics and fine structure of dough and underlying mechanism were elucidated by rheometer, scanning microscope and molecular spectroscopic method. Results showed that compared with native dough (without exogenous rapeseed oil), the addition of rapeseed oil changed the fine structure, improved extensibility, but reduced viscoelasticity of the dough. Moreover, high addition especially 20 wt% oil (based on wheat flour) significantly changed gelatinization and retrogradation behaviors of the dough, whilst disrupted gluten network and increased random coil content (32.1%) of dough except that decreased its α-helix (21.2%), β-sheet (23.1%), disulfide bond (7.9 μmol/g) compared with native dough which were 16.3%, 29.2%, 33.1%, 11.0 μmol/g, respectively. Results in the study could provide a certain understanding for application of vegetable oils in wheat-based products.