Improving the extraction efficiency and functional properties of wheat germ protein by ultrasound-assisted

Abstract

his study optimised the conditions for ultrasound-assisted extraction (UAE) of defatted wheat germ protein (WGP) and evaluated its effect on the functional properties. Single-factor and orthogonal experiment designs were combined to optimise the UAE extraction condition. The extraction of WGP reached the highest level, at 88.66%, with a solid : liquid ratio of 1 : 25 g.mL-1, pH value of 9.0, ultrasonic time of 10 min, and ultrasonic power at 400 W. Under these conditions, albumin, globulin, prolamin, and glutenin accounted for 32.26, 28.52, 5.42, and 22.40% of total protein, respectively. In addition, this study compared the functional properties of WGP extracted by UAE with the results based on a commercially available soy protein (SP) isolate (SPI). The UAE of WGP had better oil absorption, foaming, and emulsifying properties. Therefore, UAE is a promising technique for food protein extraction because it can change the protein efficiencies and properties of the extract.

Keywords

• wheat grain
• orthogonal experiment design
• single-factor experiment design
• protein
• cavitation and mechanical effects