Abstract
To improve the viscoelastic properties of Feruloylated Water Extractable Arabinoxylan (F-WEAX) gels, F-WEAX was crosslinked using a laccase in the presence of cellulose nanocrystals (CNC). The CNC/F-WEAX weight ratio ranged from 0 to 1.5, with a constant F-WEAX concentration of 1 % (w/v). The addition of CNC increased gel stiffness and the elastic modulus scales as [CNC] 3 . CNC also affects the relaxation behaviour, enhancing significantly the loss factor at low frequencies. QCM-D measurements shows that F-WEAX adsorbed irreversibly onto CNC with the same affinity as non-feruloylated ones. In the presence of CNC, the action of laccase produces double the quantity of elastically active oxidation products, which are the dimer and trimer forms of ferulic acid (FA). As a consequence, the swelling capacity of the F-WEAX-CNC gels decreases, however less than anticipated from the increase in shear modulus. The synergistic enhancement of elasticity, while maintaining swelling capacity, is tentatively attributed to the formation of high-functionality junctions through the irreversible adsorption of F-WEAX onto CNC.