Aleurone cells are the primary contributor to arabinoxylan oligosaccharide production from wheat bran after treatment with cell wall‐degrading enzymes

Summary Arabinoxylans and in particular arabinoxylan oligosaccharides (AXOS) from wheat are recognised for their prebiotic potential. A high‐yield, non‐chemical production of AXOS is therefore of interest when producing functional foods. This study investigated the enzymatic production of AXOS from wheat bran with the aim of establishing the main fraction contributing to production of AXOS. Fractions of wheat bran, outer pericarp and aleurone with two different purities were treated with the cell wall‐degrading enzymes: xylanase, cellulase and β‐glucanase. The yield of solubilised arabinoxylans upon treatment was greatest in the most pure aleurone fraction (164 g kg−1) and lowest in the outer pericarp fraction (15 g kg−1). The yield was mainly recovered as AXOS rather than soluble arabinoxylans and was negatively related to the arabinose/xylose ratio found in the raw material. In conclusion, wheat aleurone cell walls are the main contributor to the production of AXOS from wheat bran and this seems to depend on the A/X ratio of the raw material. Adding cell wall‐degrading enzymes to different fractions of wheat bran caused a release of arabinoxylan from the cell wall matrix. The highest release of arabinoxylan and arabinoxylan oligosaccharides was observed from wheat aleurone and seemed to depend on arabinose/xylose ratio.