Grafted ferulic acid dose-dependently enhanced the apparent viscosity and antioxidant activities of arabinoxylan

Ferulic acid (FA) of various ratios was successfully tagged onto arabinoxylan (AX) molecule by N,N′-carbonyldiimidazole (CDI) radical grafting reaction. The structural characterization of conjugates was conducted using methylation analysis, UV–vis, FT-IR and 1H NMR spectroscopy. The linkage patterns of AX before and after conjugation were similar. However, tagging FA onto AX significantly decreased the water solubility & Mw, whereas the apparent viscosity & antioxidant activity of AX were significantly enhanced. All these changes were positively correlated with the degree of attached FA. This study showed that trace amounts of phenolic compounds play a critical role in affecting the functional and bioactive properties of non-starch polysaccharides, which pave the way to develop novel dietary fibres with targeted functional and/or physiological properties.