Study On Purification Of Chickpea Isoflavones And Its Application

Chickpea, one of species of Cicer, which belongs to Family Leguminosae, is an annual or perennial herb growing in arid and semi-arid area of the world, it is also the second largest consumption legume and widely cultivated. The resource of isoflavones in nature is limited, which is so contained in chickpea, its content is up to 0.33% in its germinated seeds. In nutriology, it is the most attractive nutrition in it.In this paper, the specific extraction methods of total isoflavones from chickpea was studied. Single factor’s effect to the total isoflavones’ harvest was researched, such as the chickpea’s burgeon, the extraction solvent, the concentration of extraction solvent, the extraction time. Finally through the Orthogonal experiments, the optimum process of extraction was obtained: choosing the germinant chickpea powder, degreasing by petroleun ether, using 65% ethanol and extracting the chickpea powder for two times (2 hours per time)under 85°C, then the isoflavones’ gain rate is 0.3234%. while the isoflavones’ gain rate of the non-germinant chickpea is 0.2795%. We Attempted to extract isofavones by microwave, and found out that treating the degreased chickpea powder by microwave for 3 minutes can significantly decrease the usage of solvent and increase the total isoflavone’s gain rate.In the filed of refining the chickpea isoflavones, a safe, effective and low cost method for refining isoflavones from the chickpea was established. The raw isoflavones solution was extracted by ethanol from the degreased chickpea powder and then refined by 6 kinds of macroporous adsorption resins. The results showed XAD-2 was the best resin for refining isoflavones from chickpea, then the adsorption kinetics and thermodynamics of XAD-2 resin for chickpea isoflavones were studied. The adsorption isotherm of XAD-2 resin was obtained, as well as its adsorption and eluting property to chickpea isoflavones. The conclusion was that XAD-2 resin is suitable for refining the chickpea isoflavones, a reasonable yield and purity of the terminal product which is 67% and 21.29% respectively can be reached.In the filed of testsing isoflavones products, the antioxidation ability of chickpea isoflavones satisfided the results that adding 0.4mg isoflavones into 10mg axunge in the oven can antioxidize for 4 days. The reduction property of chickpea isoflavones was tested by means of color reaction Fe3+ reduced into Fe2+ and equivalent with Vc. The chickpea isoflavones also showed activities of scavenging actions to hydroxyl free radicals(·OH) generated by Fenton reaction and to bacterium compared with 1% penicillin. The scavenging activity to hydroxyl free radical was represented by the content of scavenging 50 % of all radicals ( Ec50). and the scavenging activity to bacteria resistance was determined by means of inhibition zone. The Ec50 of chickpea isoflavones to·OH was 21.36mg/ L. and the effect of chickpea isoflavones on antibacterial property was evident.In the filed of modifyings isoflavones products, we investigated and compared the inclusion process of the chickpea isoflavones-β-cyclodextrin and chickpea isoflavones-hydroxypropyl-β-cyclodextrin. and then identified them. The optimum preparation condition was studied by orthogonal test with encapsulation rate and percentage of isoflavone content as the index of evaluation. The inclusion compounds were prepared by grinding technique and staturated solution method, The inclusion compounds were identified by thin-layer chromatography (TLC) and infrared spectroscopy (IR). The effect of inclusion by HP-β-CD was better.This paper conducted a systematical study into the purification of chickpea isoflavones and provided experimental datas for cultivated chickpea as a traditional medicine in clinic.