Comparative study of thermo-mechanical, rheological, and structural properties of gluten-free model doughs from high hydrostatic pressure treated maize, potato, and sweet potato starches

Effects of high hydrostatic pressure (HHP, 100, 300 and 500 MPa for 30 min at 25 degrees C) treated maize (MS), potato (PS), and sweet potato (SS) starches on thermo-mechanical, rheological, microstructural properties and water distribution of gluten-free model doughs were investigated. Significant differences were found among starch model doughs in terms of water absorption, dough development time, and dough stability at 500 MPa. Total gas production of MS, PS and SS doughs was significantly increased from 541 to 605 mL (300 MPa), 527 to 568 mL (500 MPa) and 551 to 620 mL (500 MPa) respectively as HHP increased. HHP increased storage (G ') and loss (G '') modulus in terms of rheological properties suggesting, the higher viscoelastic behavior of starch model doughs. The dough after 500 MPa treatment showed lower degree of dependence of G ' on frequency sweep suggesting, the formation of a stable network structure. In addition, continuous abundant water distribution and uniform microstructure were found in MS (300 MPa), PS (500 MPa) and SS (500 MPa) doughs for 60 min fermentation. Thus, the starches after HHP show great application potential in gluten-free doughs with improved characteristics.