"Formation of Hydrogels From Antioxidative Synthetic Hydroxycinnamate Ester Conjugates Based on Corn Bran Arabinoxylan "

Abstract

Corn bran arabinoxylan (CAX) was extracted from corn bran and modified through conjugating to four hydroxycinnamic acids (HAs), namely ferulic acid (FA), p-coumaric acid (p-CA), caffeic acid (CA), and sinapic acid (SA). These HA arabinoxylan esters (HA-CAX-n) exhibited analogous n-degrees of substitution (DS), FA-CAX-0.31, p-CA-CAX-0.32, CA-CAX-0.32, and SA-CAX-0.31. The antioxidant capacity was evaluated by a chemical method – an oxygen radical antioxidant capacity (ORAC) assay – and cellular models – a cellular antioxidant activity (CAA) assay to healthy human skin fibroblasts (HSF). The results of the various analyses were comparable, demonstrating the order of antioxidant capability was: CA-CAX-0.32 > SA-CAX-0.31 > FA-CAX-0.31 > p-CA-CAX-0.32. HA-CAX-n gels with different crosslinking ability were obtained with the concentration of 0.5% (w/v) during oxidative gelation by laccase, SA-CAX-0.31 can form gels most easily, followed by FA-CAX-0.31, CA-CAX-0.32 and p-CA-CAX-0.32.

Valorization of Grain and Oil By-Products with Special Focus on Hemicellulose Modification

“…In other types of esterification reactions, Li [ 69 ], for example, used four kinds of hydroxycinnamic acids (FA, p-CA, SA, CA) to modify arabinoxylan (CAX) extracted from corn bran through esterification reactions. The study found that CA-CAX-0.32, which contains more phenolic hydroxyl groups and hydrogen ions, exhibits antioxidant properties and can inhibit oxidative damage to cells caused by free radicals.…”

“…The laccase catalyzed the oxidative cross-linking of ferulic acid groups to form covalent di-ferulic acid cross-links, producing strong hydrogels. Li [69] used laccase (derived from Trichoderma and oyster mushrooms) as a cross-linker to cross-link hydroxycinnamic-acid-esterified corn bran arabinoxylan at 25 • C. The author noted that methoxy and hydroxyl groups provide a higher cross-linking density, and the hydrogels exhibited good mechanical properties and biocompatibility, with broad application prospects in antioxidant skincare products and functional foods. Yilmaz-Turan et al [114] extracted arabinoxylan (FAX) from wheat bran and formed functional hydrogels through laccase oxidative cross-linking.…”