Production of feruloylated arabinoxylo-oligosaccharides from maize (Zea mays) bran by microwave-assisted autohydrolysis

Maize bran was treated with microwave irradiation (160–200 °C for 2–20 min) to release feruloylated arabinoxylo-oligosaccharides (AXOS). Lower temperatures and shorter treatment times were consistent with low AXOS yields, while higher temperatures and longer reaction times also resulted in low yields, which were contaminated with increasing levels of monosaccharides, free ferulic acid, and furfural. Maximum release of AXOS, accompanied by low production of monosaccharides, free ferulic acid, and furfural, occurred with treatment at 180 °C for 10 min or 200 °C for 2 min. Under these conditions, about 50% of the initial arabinoxylan content could be released as AXOS, containing a wide variety of molecular weights. AXOS were highly feruloylated, containing 6.62 and 8.00 g of esterified ferulate/100 g of AXOS. These feruloylated AXOS may provide health benefits, including prebiotic effects and prevention of detrimental oxidation reactions. The evaluation of these benefits will be the subject of future research.