Improvement of arabinoxylan isolation from barley husks

A method of extracting arabinoxylan from barley husks has previously been developed, but was found to suffer from three problems, namely: starch was dispersed in the aqueous phase during steam pretreatment, the yield of extracted arabinoxylan with high molecular mass was low in the steam pretreatment step, and there was high filtration resistance in the clarification step. This paper presents possible solutions to these problems. Starch was removed prior to steam pretreatment by boiling the husks in water for 1 h. This treatment decreased the content of glucan in the aqueous phase after steam pretreatment by 75%. The yield of arabinoxylan with a molecular mass greater than 5 kDa was increased from 5% to 25% by using alkaline impregnation (1 wt.% NaOH). A vibrating shear-enhanced microfiltration unit was proven to be an alternative method to traditional filtration for clarification of the aqueous phase.