Preparation of inulin and phenols-rich dietary fibre powder from burdock root

Abstract

The simultaneous ultrasonic/microwave assisted extraction (UMAE) of inulin and production of phenols-rich dietary fibre powder from burdock root was studied. It was found that UMAE required a much shorter extraction time than conventional stirring extraction. And the recovery of inulin increased with the increase of microwave power as well as solvent to solid ratio. A comparison of scanning electron microscopy images of raw and simultaneous ultrasonic/microwave treated burdock root indicated microfractures and disruption of cell walls in burdock root flakes. The dietary fibre powder prepared from the residue of burdock root after inulin extraction was rich in phenols (302.62 mg GAE/100 g powder). The results showed that drying temperature in the selected range did not significantly affect the hydration properties. The relatively high water retention capacity, swelling capacity and oil-holding capacity of the dietary fibre powder indicated its broad use as a modifier of properties of formulated products.