بررسي تجربي و مدل سازي رياضي استخراج فوق بحراني ديوزژنين از ميوه ي گياه تريبيولوس

چكيده انگليسي :

Experimental and Modeling Investigation of Supercritical Extraction of Diosgenin from Tribulus Terrestris Fruit Ehsan Bataghva e bataghva@ce iut ac ir March 9 2011 Department of Chemical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Seyyed Mohammad Ghoreishi Assoc Prof Email ghoreshi@cc iut ac ir Ali Akbar Dadkhah Assist Prof Email dadkhah@cc iut ac ir Abstract Insulin has a key role in the treatment of diabetes mellitus which is growing into epidemic proportions worldwide For the treatment of type I diabetes and many patients with type II diabetes injection of one or more doses of intermediate or long acting insulin is necessary to satisfy the patient s basal requirement of insulin Diosgenin is one of the most important precursors in the synthesis of steroidal drugs and it has been reported to possess many pharmacological activities such as antidiabetic activity anticancer cardiovascular action and antimalarial activities It also plays an important role in the control of plasma cholesterol level Tribulus terrestris L is one of the most important resources for diosgenin production The occurrence of saponins flavonoids alkaloids lignanamides and cinammic acid amides has been reported in T terrestris Diosgenin exists in T terrestris fruit in a combined glycosidal form of steroidal saponin and traditionally diosgenin is produced by acid hydrolysis of T terrestris fruit Supercritical fluid extraction especially supercritical carbon dioxide extraction as an efficient extraction method has attracted attention during the last decades as its advantages include being non explosive non toxic and available in high purity with low cost non solvent residues In this study supercritical carbon dioxide extraction of essential oil and diosgenin from T terrestris fruit was performed Response surface methodology was employed to optimize the extraction parameters The effects of pressure temperature flow rate of CO2 and extraction time on the recoveries of essential oil and diosgenin were investigated in the range of 10 30 MPa 35 55 o C 0 3 1 5 ml min and 40 160 min respectively Response surface analysis showed that the data were adequately fitted to second order polynomial model The linear and quadratics terms of pressure and dynamic time as well as the interaction between pressure and temperature had significant effects on the recoveries of essential oil and diosgenin It was predicted that the optimum extraction conditions within the experimental ranges would be the extraction pressure of 23 3 MPa and temperature of 47 7 o C with flow rate of 0 74 ml min and extraction time of 130 9 min Under such conditions the recoveries of essential oil and diosgenin were predicted to be 91 63 and 86 12 respectively Moreover in the present study a mathematical modeling for extraction of diosgenin from T terrestris fruit using supercritical carbon dioxide was performed The model was developed utilizing diffusion controlled regime in the pore and film mass transfer resistances with axial dispersion of the mobile phase at dynamic conditions The mass transfer parameters i e effective pore diffusivity film mass transfer coefficient and axial dispersion along with the solubility parameter were chosen as the model parameters The first three mass transfer parameters were predicted using nondimensional equations from the literature Henry law was used to describe the equilibrium state of solid and pore fluid phases Genetic algorithm was applied to determine the optimal value of Henry coefficient such that to minimize the absolute average deviations AAD between the experimental and predicted extraction recoveries The values of absolute average deviations AAD were in the range of 2 8 44 which is the indication of a very good compatibility and validation for the developed model Key Words Supercritical extraction Diosgenin Tribulus terrestris Response surface methodology Mathematical modeling

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بررسي تجربي و مدل سازي رياضي استخراج فوق بحراني ديوزژنين از ميوه ي گياه تريبيولوس

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