Studies On Preparation And Antioxidant Activities Of Procyanidins From Faba Bean Episperm

China is growing a large faba bean. There are a large number of faba bean skinis discarded in processing.Howerve faba bean skins are rich in proanthocyanidin,has not been effectively utilized. In the paper, the author studied extracting,purification, structure elucidation and antioxidant activity of faba bean epispermproanthocyanidinTaking into account of the chemical characteristics of proanthocyanidin, theauthor combing the advantage of microwave assisted and ethanol reflux extraction.Selected microwave power, microwave time, add water, extraction solvent, thematerial liquid ratio, extraction temperature, extraction time for a single factorexperiment. Selected the solid-liquid ratio, extraction temperature, extraction timefor response surface experiment. The results showed that: the best technology formicrowave140W, heating the50s, the amount of water2mL/g, the solid-liquidratio21mL/g, temperature55℃, extraction time72min, the extraction rate up to94.53%.Studing the mechanism of extractting,showed that proanthocyanidins ismore suitable for low power handling.The lipids, pigments and gum solution, acetone organic, and protein can beremoved by Acetone and petroleum, the purity is about47.2%and58.77%. Fababean episperm proanthocyanidins were purified by filtering out the AB-8macroporous resin, the most suitable concentration of the sample injection rate,elution solvent volume fraction, elution speed are8mg/mL,2BV/h,70%ethanol,2BV/h. Highest elution rate of up to95.25%, purity is94.33%.After the faba bean episperm proanthocyanidin are purited by organic solventand macroporous resin, analyzed it by infrared spectroscopy. The results show thatthe characteristic vibration of the faba bean episperm proanthocyanidin areconcentrated in the1000¹700cm^-1and500⁸00cm^-1range, showing strongphenolic hydroxyl absorption peak near3400cm^-1,1400¹600cm^-1is the faba beanepisperm proanthocyanidins benzene ring （aromatic ring） and the phenolic hydroxyl group in the skeleton stretching vibration region at the strong absorptionin the fingerprint region700⁹00cm^-1a strong absorption. The C-O-C stretching inproanthocyanidin’s C ring has vibration absorption peak from1000to1400cm^-1range. There are not appear strong carboxylic acid vibration at2927cm^-1and1699cm^-1, indicating that the use of AB-8macroporous resin with the aqueous phasesample, the alcohol phase elution can effectively remove the initial extract ofphenol hydroxy acid or ganic acids.Through the composition of the Purification of the faba bean epispermprocyanidins analyzed by mass spectrometry, and speculated that the mainsubstance detected catechins and a variety of dimer, trimer, tetramer, five polymers,and some anthocyanin. The main are proanthocyanidins, procyanidins （PC） and theoriginal fly grass （PD） substances.After it is purified by macroporous resin, faba bean epispermproanthocyanidin through the polyamide by gradient elution.Detection of variouscomponents on the fragmentation pathway of the isolated monomer in the negativeion mode. Structure and possible enantiomers of two spectra of varioussubstances, the monomer （m/z289）, dimer （m/z577, m/z593, m/z609）, trimer（m/z865）are derivated, while the trimer （m/z881, m/z897） of the two spectra cannot determine its structure, only given its possible structure.Faba bean episperm proanthocyanidin has a strong ability of scavenginghydroxyl radicals, superoxide anion, and inhibition of lipid oxidation and reductioncapacity, and significantly better than the same concentration of Vc. Because of thecatechins unit, making it’s antioxidant activity more than BlackBerry, sorghum,grape seed sources such as the procyanidins.