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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 (302.62mg GAE/100g 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. [Copyright &y& Elsevier]

This research evaluated the effects of enzymatic-chemical extraction (EC-SDF), subcritical water extraction (SW-SDF), and ultrasonic-chemical extraction (UC-SDF) processes on the yield, chemical composition, structural characterization, flow behavior, physicochemical, and functional properties of soluble dietary fiber (SDF) from defatted coconut flour (DCF). The optimum conditions of these three extraction methods were evaluated by response surface methodology. Compared with EC-SDF and UC-SDF, SW-SDF had the maximum yield (13.99 ± 0.12 g/100g). The structural results indicated that SW-SDF and UC-SDF possessed more complex and porous structures than EC-SDF and DCF. Moreover, they showed smaller molecular weight, stronger gelling property, higher thermal stability, and lower crystallinity. A monosaccharide composition analysis indicated that the major sugars in EC-SDF, UC-SDF and UC-SDF were mannose and galactose. Notably, the SW-SDF demonstrated the highest water and oil holding capacity, glucose adsorption, pancreatic lipase inhibition, cholesterol adsorption, and nitrite ion adsorption capacities. The above results suggest the defatted coconut flour to be a potential functional food and a possible source of cheap natural dietary fiber. • Soluble dietary fiber was recovered from the defatted coconut flour. • Three different methods were used to extract soluble dietary fiber. • The composition, structure and properties of the extracts were compared. • Subcritical water extraction method had the highest physicochemical properties. • The defatted coconut flour has great potential for the application in functional food industry. [ABSTRACT FROM AUTHOR]