Research On Extraction,Antioxidant Activity And Stability Of Polyphenols In Oat Bran

Oat is a genus of Gramineae A vena, protein,fat, vitamins, dietary fiber contents of oats are the highest in cereals. Oats contain a variety of active nutrients, possess rich nutrient value and healthy effect. Oat bran from oats industry by-products almost is as animals feedstuff.Antioxidant activity is one of oat properties, major antioxidant active components is polypHenols which mainly distribute Oat bran. So oat bran was used as material to separated polypllenolics.which is significent to increase oat utilization percent and develope new oat nutrient food and high value-added product.In this study. First of all. the polypHenols of oat bran was extracted by solvent and the extraction conditions were optimized; second the crude polypHenols extracted was purified by macroporous resin adsorption and the conditions were optimized.the constituent of polypHenols witch was purified was identified by UV-Vis. third antioxidant activity and stability were determinated. The major findings were presented as follows:(1)The extraction of polypHenols from oat bran and the optimized of the conditions:From the experiments of solvent extraction comparison and the single factor experiment. The effect of pH, extracting times was studied. The optimization technics Parameters by the Response Surface Method on the basis of above results were follows:ratio of solid and liquid 1:22, ethanol concentration 50%, extracting time 3 h, extracting temperature 85 ℃, extraction rate is 7.4832 mg/g.(2)The purification of crude polypHenols of oat bran:the D-101 resin was selected from 10 kinds of macroporous adsorbent resins as a suitable material for the purification of oat bran polypHenols by static adsoiption and elution research. The D-101 resin confirmed to have the best adsorption and elution effect. It took 5 h to achieve saturation adsorption, the static saturated adsorption capacity of D-101 resin was 64.01 mg/g dry resin. D-101 resin could well fit Langmuir and Freundlich equation.70%(volume fraction) ethanol was a suitable solvent as elution. The adsorption capacity of the resin was biggest at a feeding concentration of 3.0 mg/mL and a flow rate of 1.0 mg/min.70% ethanol could elute the polypHenols adsorbed on the column well, elution radio was 76.71%.(3)Identification of polypHenols of oat bran:the polypHenols characteristic was obvious in the color reaction, Scaned by UV spectrometer also was consistent with reported, polypHenols could was tentative identified.(4) Determination of antioxidant activity of polypHenols of oat bran:The antioxidant activities of polypHenols of oat bran were studied through six different systems:the hydroxyl radical system, 1,1-dipHenyl-2-picrylhydrazyl (DPPH) radical system, superoxide radical system, nitrite(NO2-)deoxidize activity, lard system.The results showed that oat bran polypHenols had strong capacities of antioxidation.(5)Determinated of stability of:polypHenols of oat bran:The stability of polypHenols of oat bran is good, polypHenols of oat bran was stable with temperature, pH, carbohydrate、 stabilizing agent, preservative, was decreased by the factors of light, few metal ions (Cu2+ Fe2+),H2O2.