Wheat bran arabinoxylan and whey protein isolate conjugates: Synthesis, characterization, and applications in O/W emulsions

This study explored the production of whey protein isolate (WPI) and arabinoxylan (AX) covalent conjugates (WA) via Maillard reaction under varying reaction times and AX/WPI molar ratios. The structural and functional properties of the conjugates, including their ability to emulsify and stabilize oil and water emulsions, were measured. Overall, the conjugates prepared with a AX/WPI molar ratio of 4:2 and heating treatment for 5 h exhibited the highest grafting degree (15.74 %) as well as the best emulsifying properties. The emulsifying activity and emulsion stability of WA-3 at 0.5 wt% were 1.78-fold and 5.78-fold higher than those of 15 wt% commercial gum arabic, respectively. These findings indicated that optimizing the Maillard conjugation process under specific conditions could enhance the use of WPI-AX conjugates as natural emulsifiers in the food industry. • Whey protein isolate (WPI) and arabinoxylan (AX) covalent conjugates were prepared. • The structural and functional features of the conjugates were investigated. • The conjugates showed higher emulsifying and foaming properties compared to WPI or AX. • Emulsifying activity of WA-3 at 0.5 wt% were 1.78-fold higher than 15 wt% gum arabic. • Emulsifying stability of WA-3 at 0.5 wt% were 5.78-fold higher than 15 wt% gum arabic.