Study On Extraction, Separation Of Soybean Isoflavone And Kinetic Mechanisms And Thermodynamics Mechanism For The Extraction

Isoflavones are phytoestrogens that are present in soybeans.Researches have been found that soy isoflavones demonstrate many physiological functions upon human bodies.Specially,the ability of isoflvaone to prevent cancer and other chronic disease are much concerned.Isoflavones are the best drug materials used in treatment of cardiovascular diseases so far.In this paper,the optimal technological condition to gain products of isoflvaone,the kinetics and thermodynamic mechanism for using organic solvent to extract isoflavone from soybean residuals are studied.1.The soxhlet extraction experiment,ethanol extraction and microwave assisted extraction were used.Meanwhile the three extraction methods were compared. Furthermore,some researches were done on the effect of different extract solvent,the different concentration of solvent,the different extraction time etc.Comparing the effectiveness of three methods of extraction,the ethanol extraction was selected.The optional conditions were as follows:the concentration of ethanol was 80%,the extraction time was 2h,the temperature was 80℃and the materials ratio was 1:30.2.In order to futher separate and purify the soybean isoflavone,the absorption equilibrium and kinetics of soybean isoflavone by using macropore resin AB-8 were studied.It had been found that the absorption isotherms at different temperatures and the absorption kinetics equations with liquid soybean isoflavone concentration and time for the parameters.When the AB-8 resin column absorbed isoflavone,better effects can be absorbed in the condition of higher concentration and lower elution rate. In order to futher separate genistein from the waste residue of the soybean,the proposed purification route was studied.The impurity could be cleaned elementarily by combining isoelectric point precipitation,centrifugation at 3000 rpm.The others such as sugars could be eluted by distilled water from the macroporous adsorption resin column.It had been found that lipid and protein could be cleaned mostly.The obtained proper elution process was as follows:the distilled waterâ†'20%ethanolâ†'70%ethanol,the first different elution solvent on the column elution;40%ethanolâ†' 70%ethanol,the second different elution solvent on the column elution.The determination of HPLC showed that genistein with purity of 90%was obtained.3.The kinetic mechanism of the soybean isoflavones extraction process was researched by ethanol extraction.The kinetic of solvent extraction process agreed with the first-order rate equation.The experiments for extracting soybean isoflavones from the waste residue of the soybeans were studied under different conditions to evaluate the kinetic equation based on Fick's first law of diffusion.Experimental data could match the kinetic equation.It supplied a valuable theory basis for the comprehensive utilization and extraction of active constituents from the waste residue of the soybeans.4.The thermodynamics mechanism of the soybean isoflavones extraction process was researched by ethanol extraction.On the base of experiments,a simple model was applied to calculate partition coefficients K,â–³H,â–³S andâ–³G of the constituents determined for ethanol extraction.The results showed that the soybean isoflavones extraction was endothermic and entropy increase process,and theâ–³G decreased with the temperature increasing.