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In this paper, buckwheat bran flour as raw material, mainly flavonoids solvent extraction, microwave extraction, ultrasonic extraction three extraction methods, through the single factor experiment and response surface test to determine the optimal parameters of the three extraction methods, and three extraction methods; macroporous resin were purified crude extracts from buckwheat bran flavonoids, through testing to determine the optimum parameters of AB-8 macroporous adsorption resin and purified and by seven different systems bitter buckwheat flavonoids antioxidant properties. The main results are as follows: 1.AlCl 3 Determination of total flavonoids results stable the standard rutin, 0-0.2mg/mL concentration range better linear standard curve equation Y = 0.2936X 0.0025, its R 2 value of 0.9994; the AlCl 3 method of high-precision, reproducibility, repeated measurements RSD value of only 1.222%; higher recovery rate, in five recovery test, the average recoveries of 102.83%, RSD value of 2.57%. Optimum process parameters of the organic solvent extraction of flavonoids: extraction of 4.8h, liquid-solid ratio 50:1, extract 2, the solvent pH 10, extraction temperature 67.2 ℃, ethanol concentration of 60.1%, extraction rate 5.48%. The optimal parameters of microwave-assisted extraction of flavonoids: prepreg 19.9min, microwave power 600W, microwave processing 20min, 54.1% of the ethanol concentration, liquid to solid ratio 34.7:1 extract 1, borax amount of 0.002g flavonoids extraction rate was 9.23%. The optimal parameters of ultrasonic assisted extraction of flavonoids: ultrasonic power 750W, ultrasonic processing 25.3min, 48.8% of the ethanol concentration, ratio of liquid to solid 24:1 extract three times, ethanol solution pH of 11 flavonoids extraction rate 7.56%. 5.AB-8 type macroporous resin has good adsorption and desorption ability of flavonoids. The optimum parameters of purified flavonoids: adsorption conditions on the column rate 1.0mL/min, the adsorption feed concentration 1.202mg/mL pH value of 6.5; the desorption condition is desorption solvent 70% ethanol solution, elution flow rate of 0.5 mL / min. By the reaction of flavonoids with specific reagents color map inspection and test, test and flavonoids UV spectral characteristics initially identified from buckwheat bran separating purified natural flavonoids flavonols flavonoids. Seven different systems in vitro antioxidant experiments show that sample A (buckwheat bran flavonoids crude extract), sample B (buckwheat bran in flavonoids purified), seven systems have certain anti oxidation resistance, but with increasing concentration enhanced. H 2 O 2 system, sample B and Vc scavenging Sample A considerable weaker than sample B and Vc stronger than BHT. In the system of the hydroxyl radical (OH), at the same concentration, the samples A, B scavenging OH and are weaker than Vc. 2 system, Vc Clear strongest superoxide anion radical, at low concentrations, there is a strong superoxide anion radical the ability of the superoxide anion O . Samples A, B and BHT in the test concentration range of the superoxide anion radical scavenging effect in general, the highest clearance rate of only 51.46%, 59.61% and 49.93% respectively. Reducing power system, the sample A reduction ability and BHT less, reducing power of the sample B was significantly stronger than that of the sample A, Vc and BHT. Nitrite system, Vc nitrite scavenging effect than sample A, B and BHT stronger. In the alkyl group R in the system, the samples A, B, and Vc, BHT alkyl radicals have certain scavengeability, but not obvious. The DPPH · System VC DPPH · radical scavenging rate reached 85.31%, the samples A and B of the clearance rate reached 57.22% and 50.43%, respectively, is BHT, 2.5 times and 2.2 times.
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