- Arabinoxylan is a complex, plant-derived polysaccharide that belongs to the hemicellulose family and is widely found in the cell walls of cereal grains such as wheat, rye, barley, oats, and maize.
- Structurally, it consists of a linear backbone of β-(1→4)-linked xylose units, which may be substituted at the C-2 and/or C-3 positions with arabinose residues. These arabinose side chains can be further esterified with ferulic acid, which enables cross-linking with other wall components like lignin or other polysaccharides. This highly branched and variable structure makes arabinoxylans chemically diverse, with their exact composition depending on plant species, tissue type, and growth conditions.
- In the plant cell wall, arabinoxylan contributes to strength, flexibility, and defense. It interacts with cellulose microfibrils and lignin to form a resilient structural network that protects cells against mechanical stress and pathogen attack. Ferulic acid-mediated cross-linking between arabinoxylan chains also influences wall rigidity and resistance to degradation. In cereal grains, arabinoxylan is especially abundant in bran layers, where it helps regulate water retention, germination, and seed protection.
- From a nutritional perspective, arabinoxylan is classified as a dietary fiber. Humans cannot enzymatically digest the β-(1→4)-xylosidic bonds, so arabinoxylan reaches the colon largely intact, where it undergoes fermentation by gut microbiota. The fermentation process produces short-chain fatty acids (SCFAs) such as acetate, propionate, and butyrate, which play key roles in gut health, immune modulation, and systemic metabolism. Arabinoxylan-derived oligosaccharides (AXOS), generated through enzymatic or partial hydrolysis, are well-recognized as prebiotics, selectively stimulating beneficial bacterial populations like Bifidobacterium. This makes arabinoxylan and its derivatives valuable functional ingredients for improving digestive health and overall well-being.
- In the food industry, arabinoxylan influences both nutritional quality and technological properties of cereal-based products. In breadmaking, arabinoxylans affect dough viscosity, water absorption, and crumb texture. Soluble arabinoxylans can enhance loaf volume and softness, while insoluble forms may interfere with gluten networks, impacting bread quality. Beyond baking, arabinoxylan is being explored as a natural hydrocolloid for thickening, stabilizing, and improving texture in various food products. Its ability to increase dietary fiber intake also supports its inclusion in health-oriented foods and supplements.
- Arabinoxylan also holds promise in biotechnology, pharmaceuticals, and materials science. Feruloylated arabinoxylans are being studied for antioxidant, anti-inflammatory, and cholesterol-lowering activities, suggesting therapeutic potential. Their gel-forming and film-forming abilities make them attractive for developing biodegradable coatings, edible films, and controlled-release drug delivery systems. In the biofuel sector, arabinoxylan-rich agricultural by-products are considered valuable feedstocks for the production of fermentable sugars, contributing to renewable energy development.
