Wheat bran is a major by-product of cereal production that still has limited use for advanced nutritional and material applications. A sequential process using subcritical water, membrane filtration and selective enzymatic treatments has been designed for the combined fractionation of functional high molar mass hemicelluloses (over 10 5 g mol −1 ) and oligosaccharides from wheat bran. This process not only offers increased total solid yield compared with conventional protocols based on alkaline extraction, but it also preserves the inherent functionalities of the phenolic groups that substitute the carbohydrate structures of the extracted hemicelluloses. Feruloylated arabinoxylans (F-AX) with high molar mass and significant radical scavenging activity can be isolated from the subcritical water extract. Structurally different oligosaccharides, including mixed-linkage β-D-glucan oligosaccharides (BGOs) and arabinoxylo-oligosaccharides (AXOs) can be recovered from the eluent after membrane filtration. The crosslinked residue after subcritical water extraction was further treated with xylanolytic enzymes to release valuable feruloylated arabinoxylo-oligosaccharides (FAXOs). The oligo-and polysaccharide fractions isolated from this sequential process show great potential for use as prebiotic or platform chemicals, and as polymeric matrices for carbohydrate-based materials with radical scavenging properties, respectively. IntroductionCereal processing generates large volumes of by-products that have not been exploited to their full potential for advanced nutritional and material applications. 1 Each ton processed by the wheat milling industry generates up to 0.25 tons of wheat bran that corresponds to 14-16% of the cereal kernel. 2 Due to its content of valuable biomacromolecules, such as polysaccharides (mainly hemicelluloses) and phenolic compounds, wheat bran has gained renewed interest as a raw material to be used in second generation biorefineries. 2-4Xylan is one of the most abundant biopolymers in nature as a major non-cellulosic component of plant cell walls. In particular, arabinoxylan (AX) constitutes the main hemicellulose in grasses and cereal grains, with an average composition of 20-40% depending on the species and tissue considered. View Article OnlineView Journal | View Issue substitutions. 9 Other methods have also been developed for the extraction and purification of AX from cereal by-products, including acid pretreatment, 11 microwave assisted extraction, 12 ultrasound assisted extraction, 13,14 and steam explosion extraction. 10,15 As an alternative, subcritical water extraction (SWE), also called pressurized hot water extraction (PHWE), appears as a promising green method for the isolation of hemicellulose fractions with preserved molecular functionalities and high molecular weight. The use of subcritical conditions (at temperature below critical point and pressure high enough to maintain liquid state) changes dramatically the properties of water, including density surface tension, polarity, vis...

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