Ultrasonic-assist Extraction Of Flavonoids From Germinated Brown Rice

The germinated brown rice is the wet product or the dried product which is composed of germ and endosperm including bran. It is obtained when the high quality brown rice is socked on certain condition and growns to0.5mm-lmm buds. Many physiological activity materials are increased in germinated brown rice, especially the falconoid which have better antioxidation. In this paper, extraction technologies with ultrasonic-assisted organic solvent method and initial purification with XAD-2type macro-porous resin of the total flavonoids from germinated brow rice were studied. Then taking the relative inhibitory of superoxide anion as the standard, the antioxidation of the bioactivities of flavonoids and Vc is analyzied and compared.on the same level. The main results were as follows:1. Study on the extraction technology of flavonoids of germinated brown riceEthanol was chosen as the extraction solvent after comparing many organism solvent. On the basis of single factor experiment, and taking flavonoid content in germinated brown rice as response value, Box-Behnken response surface analysis was adopted to construct the quadratic regression model. The results showed that the optimum extracting conditions were shown as follows:ultrasonic power270W, ultrasonic time41min, soak temperature45℃, soak time57min and the concentration of solvent59%. The extraction rate of flavonoids from germinated brown rice was0.766mg/g. The verification testing result is0.772±0.011mg/g(n=5), which has a difference of0.005with the theoretical prediction.2. Study on the purification process of flavonoids of germinated brown riceThe characteristics of static adsorption and desorption of XAD-2type macro-porous resin was observed for separating and purification germinated brown rice flavonoids;the optimum conditions were as follows: the loaded amount of germinated brown rice flavonoids was12mL with the concentration2.5mg/mL, the time of absorption was2h, the elution of water was4BV,60%ethanol as elution solvent, elution in5BV. The recovery of flavonoids in germinated brown rice was86.78%. The purity of flavonoids was come to68.7%from15.6%.3. The abilities of scavenging superoxide anion of flavonoids of germinated brown riceThe linear relation of the absorption of pyrogallol autoxidation absorbance had a good liner correlation during eight minutes. The interaction was0.4778, which increased7.94%compared with0.4369at beginning. There was anapparent increasing trend on the abilities of scavenging superoxide anion during120s at the first, and a stable inhibition from120s to480s, which directed the anti-oxidation of flavonoids of germinated brown rice were persistence. The anti-oxidation of Vc decreased strongly and almost come to zero at400s. Compared with the anti-oxidant of Vc, the anti-oxidation of flavonoids of germinated brown rice was more persistence.