Submitted to: Journal of Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/16/2009
Publication Date: 11/25/2009
Citation: Rose, D.J., Inglett, G.E. 2010. Production of Feruloyated Arabinoxylo-oligosaccharides from Maize (Zea mays) Bran by Microwave-Assisted Autohydrolysis. Journal of Food Chemistry. 119:1613-1618. Interpretive Summary: New domestic markets could exist for soluble, dietary fiber food ingredients with antioxidant activity. Maize bran is a rich source of dietary fiber and phenolic antioxidants, but application is limited due to poor solubility and fermentability. Thus, corn bran was suspended in water and subjected to high temperature treatments in a specialized microwave oven to release short and medium chain, water-soluble, dietary fibers with antioxidant activity. The optimum treatments for releasing these products were 180 °C for 10 min or 200 °C for 2 min. Short chain dietary fiber fractions released from other agricultural products with similar structures to those obtained in this study have been classified as potential prebiotics. Prebiotics include dietary fibers that selectively stimulate the growth of beneficial bacteria in the colon (for example: bifidobacteria). The longer chain dietary fiber fractions may prevent disease by providing antioxidants and beneficial food for bacteria in the distal colon, a region of the colon chronically starved for these compounds. Prior to the realization of these health benefits, these products much be purified, which will be the subject of future research. This may lead to new commercial applications for corn bran, a low value byproduct for corn dry milling, and provide new ingredients to food manufacturers for the creation of healthy foods to meet consumer demands.
Technical Abstract: Maize bran was treated with microwave irradiation (160 – 200 °C for 2 – 20 min) to release feruolyated 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, and 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 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.