Ultrasound-assisted separation of wheat flour: Enhancing the degree of separation and characterization analysis

A novel ultrasound-assisted separation (UAS) method was proposed to enhance the efficiency of gluten starch and wheat separation. Factor experiments were conducted to optimize UAS conditions. The results showed that the highest yield of gluten and starch was obtained under probe-type ultrasonic power, temperature, and time of 500 W, 35 °C, and 15 min, respectively. Compared to non-ultrasonic separation, dry basis yield and purity of gluten increased by 0.56% and 10.96%, while A-starch yield and purity increased by 21.75% and 5.56%. Additionally, UAS improved the color and the concentration of particle size distribution for gluten and starch. UAS did not affect gluten molecular weight and disrupt starch structure, but resulted in a denser structure of gluten network and caused more starch particles to be exposed. The viscoelasticity of gluten and starch separately increased and reduced with UAS, implying ultrasound aids in the dispersion of both starch and proteins.