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Licorice, the roots and rhizomes of several Glycyrrhiza species (Leguminosae), is an important natural sweetening agent and a widely used herbal medicine. In this work, six flavonoids, 5-(1,1-dimethylallyl)-3,4,4'-trihydroxy-2-methoxychalcone (1), licochalcone B (2), licochalcone A (3), echinatin (4), glycycoumarin (5) and glyurallin B (6), were isolated from the extracts of licorice (Glycyrrhiza inflata and Glycyrrhiza uralensis). Their structures were elucidated using various spectroscopic methods. To our knowledge, compound 1 was isolated from natural plants for the first time. All the isolates were tested by antioxidant and anti-inflammatory assays. Compounds 2, 4 and 5 showed strong scavenging activity toward the ABTS(+) radical, and compounds 1, 2, 3, 5 and 6 exhibited potent inhibition of lipid peroxidation in rat liver microsomes compared with the reference controls. Compounds 1-4 dose-dependently inhibited LPS induced reactive oxygen species (ROS) production in RAW 264.7 cells. Furthermore, compounds 1-5 were demonstrated to inhibit the production of nitric oxide (NO), interleukin-6 (IL-6) and prostaglandin E2 (PGE2) in LPS-induced macrophage cells. Moreover, the contents of the six compounds, in different Glycyrrhiza species, were quantified by HPLC-MS.

Extrusion cooking technology was applied for soluble dietary fibre extraction from soybean residue. Response surface methodology (RSM) was used to optimise the effects of extrusion parameters, namely extrusion temperature (90-130°C), feed moisture (25-35%) and screw speed (160-200 rpm) on the content of soluble dietary fibre. According to the regression coefficients significance of the quadratic polynomial model, the optimum extrusion parameters were as follows: extrusion temperature, 115°C; feed moisture, 31%; and screw speed, 180 rpm. Under these conditions, the soluble dietary fibre content of soybean residue could reach to 12.65% which increased 10.60% compared with the unextruded soybean residue. In addition, the dietary fibre in extrude soybean residue had higher water retention capacity, oil retention capacity and swelling capacity than those of dietary fibre in unextruded soybean residue.