Study On Separation, Purification And In Vivo Antioxidative Activity Of Anthocyanins From Black Rice

This paper was mainly focused on separation, purification and in vivo antioxidativeactivity of anthocyanins from black rice. Black rice was as raw material, anthocyanins wereextracted and purified mainly by water extraction, membrane separation and macroporousadsorption technology in turn. Main factors influencing the extraction effects ofanthocyanins were surveyed, and single-factor and orthogonal experiments (L9(34)) wereconducted respectively to optimize the extraction conditions for anthocyanins. The optimalextraction conditions were liquid-solid ratio8:1, extraction temperature40oC, extractiontime100min and feed pH value3.2.Thereafter the solution was centrifuged at4000rpm for15min. The supernate obtained was filtered with3kDa membrane to eliminate most ofproteins, polysaccharide, flavones, organic acids, etc. Subsequently, the resulting permeateobtained was filtrated with0.2kDa membrane to concentrate, and then the concentratedsolution was subjected to D101, AB-8and DM301macroporous adsorption resins,respectively. The optimal operation conditions were DM301type resin, flow velocity1.0-1.5mL/min and ethanol concentration85%. Later, a reverse osmosis membrane wasused not only to separate the anthocyanins from ethanol solution, but also to concentrate theanthocyanins. Anthocyanins were measured by High Performance Liquid Chromatography(HPLC) and an anthocyanin standard was used as control. The purity of the anthocyaninsobtained finally was95.93%and the extraction rate was up to0.86%.And then the study of in vivo antioxidative activity of anthocyanins from black rice wasconducted. Saline solution was used as carriers, and vitamin C was used as a positivecontrol group. The mice were fed with crude anthocyanin and pure anthocyaninrespectively. After30days, the spleen index and thymus index of the mice were determined,meanwhile the T-AOC, SOD, GSH-Px, MDA and hydroxyl free radical content of serum,liver, heart and kidney of the mice were determined respectively, in order to evaluate theeffects of anthocyanins on anti-oxidation ability of the mice. The result indicated thatanthocyanins could increase the spleen index and thymus index, and could alsosignificantly increase the T-AOC, activity of SOD and GSH-PX, and reduce the content ofMDA and hydroxyl radical at the same time. Therefore, the resulting anthocyanins couldimprove the ability of in vivo antioxidation in mice.