| Surfactant-assisted extraction, ultrasonic extraction and enzyme extraction were studied by taking the yield of the total flavonoids and the extracts'antioxidant as the key indexes.The process of the surfactant-assisted ultrasonic extraction of flavonoids was studied with single factor experiment and quadratic-rotation-orthogonality experiment (QROE) design,by taking the yield of the total flavonoidsas the index. The optimum conditions were as follows:ultrasonic time 30 min, extraction time 51.71 min, liquid to solid ratio20.23 mL/g, extraction temperature 97.26℃, the fitting value was 2.92%. And the experiment yield was 2.89%. The back propagation artificial neural network (BPNN) was established, which has a very well forecast performance. Under the optimum conditions, the BPNN fitting value is 2.90%. The relative mean errors of the QROE design and the BPNN were 0.96%,0.36%, respectively. When compared with other extraction methods, Tween-60-assisted ultrasonic extraction had a higher yield and efficiency, lower energy consumption.The experiments showed that the surfactant with the enzyme assisted ultrasonic extraction had a higher antioxidant with the antioxidant of the extracts as the index. Single factor experiments and the BPNN together with orthogonal experiment design were carried out to find out the optimum conditions of this method. The results were as follows:pectin 0.4 g/L, Span-60 2.0 g/L, ultrasonic time 20 min, ultrasonic temperature 50℃, extraction time 50 min, extraction temperature 90℃. The DPPH free radical clearance was 72.35% under these conditions, which is higher than other methods. |