Technology And Kinetics Study On Capsaicin Extraction By Coupled Solvent-Ion Exchange Resin

Capsaicin,the main source of spicy,widely used in people's lives in various fields.The extraction of capsaicin by using solvent-ion exchange resin coupling process was investigated in the paper.By Response Surface Methodology and the method of static adsorption kinetics experiments,the extraction regression Equation of capsaicin was established using solvent,including the connection between extraction yield and factors,and the kinetic equation of ion exchange process was gained based on different adsorption mechanism respectively.The main contents of this thesis included as follows:Firstly,the study mainly focused on the influence between extraction temperature,time and liquid-solid ratio on extraction yield of capsaicin by Response Surface Methodology to obtain the corresponding regression equation and the optimal process conditions.Secondly,the optimal pH of capsaicin adsorption on the 201×7 anion exchange resin was 5.5 by static adsorption experiments.And the adsorption isotherm at the different pH conditions was obtained according to the different adsorption mechanism.Based on the dynamic boundary model,the influence of adsorption temperature,the concentration of the solution and stirring speed on the exchange rate of capsaicin were studied.The kinetic parameters were obtained and the kinetic model of ion exchange adsorption was established to determine the mechanism of adsorption of capsaicin.The kinetic model of the ion exchange process was established by using the obtained kinetic parameters to investigate the mechanism of capsaicin adsorption.The Experimental results showed that the optimum conditions were as follows:the raw material particles size were 20 mesh by solvent extraction method,75%ethanol solution,extraction time 77min,extraction temperature 80? and the ratio of liquid to solid was 10:1.The optimal pH of capsaicin adsorption on the 201×7 anion exchange resin was 5.5.And results confirm that the adsorption isotherms of capsaicin are in accord with Freundlich when the pH is between 5.0 and 6.0,and Langmuir equation is suitable for the adsorption process when the pH is lower than 5.0 or higher than 6.0.The process of capsaicin adsorption on resin is rapid process.The rate-controlling step of the capsaicin adsorption process on resin has changed from liquid film diffusion to particle diffusion gradually.The adsorption rate constant and activation energy were 2.11×10-3s-1 and 12.7kJ/mol by calculation,and the kinetics equation of capsaicin adsorption on anion exchange resin was achieved under the optimal pH.