Modified structural and functional properties of arabinoxylan derived from brewers’ spent grain by ultrasound-assisted extraction

Abstract

Ultrasound-assisted extraction (UAE) was used to obtain arabinoxylan (AX) from brewers’ spent grain (BSG) with a higher yield, modified structural characteristics, and improved techno-functional properties. Results showed that an UAE procedure working at 400 W for 15 min under a 60% duty cycle could increase the AX yield by 52.41% compared with a traditional alkaline extraction without sonication. Concomitantly, UAE-AX developed a degraded Mw of 2741 kDa, a changed conformation of less molecular asymmetry and a decreased mean particle size from 12.56 µm to 4.993 µm. The rheological properties of UAE-AX aqueous solution were improved, leading to higher viscosity and gel-forming capacity of the AX stabilized emulsions. As a result, UAE-AX addition could reduce the mean droplet size to 6.40 µm and better stabilize the emulsion under various conditions than traditional alkaline extracted AX. Thus, the results proved UAE to be a promising method of extracting AX from BSG with valuable utilization in food processing.