Study On The Technology Conditions Of Extraction And Purification Of Limonoids In Citrus Seeds

Limonoids are a prominent group of secondary metabolites in citrus fruit and the important reason to cause bitter character in citrus fruit and juice. They possess wide application prospect because of the varied biological activities as anticancer, disinsection, antivirus and bacteriostasis.In this paper, ultrasonic extraction, hydrotropic extraction and purifying limonoids by macroporous adsorption resin method were studied. Use limonin standard sample, the qualitative research of limonoids was carried out by UV scan.The results showed that:(1) The colorimetric quantification was based on the formation of red to orange colored derivatives resulting from the treatment of limonoids fruit extract with 4-(dimethylamino) benzaldehyde (DMAB) in the presence of perchloric and acetic acids. Absorbance maxima for the limonins is found to be 470nm. The linear regression equation was y=0.0028x+0.0047, R²=0.9945. The average recoveries were 91.30%-94.48%. In addition, the method described do not require expensive equipment and take the advantages of simple operation, good stability and reliability.(2) In the experiment of the ultrasonic extraction limonoids with all kinds of organic solvent, the result show that the effect of extracting with chloroform was indicated the best, the second is acetone and acetonitrile . The safety and recycling and economic cost was evaluated integrally, acetone is choosed as extraction solvent in the experiment of the ultrasonic extraction limonoids.(3) The best conditions for the extraction techniques of limonoids in single factor experiments were: degresing time was 10 minutes,80% acetone, 30minutes, the ratio of Sample and solvent 1:40, times of extraction is twice.(4) The functional relationship between main factors and respone value were established,and the regression equation was obtained.The regression equation was as follow:Y=4.253534+0.285534*X₁+0.085791*X₂+0.114783*X₃-0.234684*X₁*X₁-0.136576*X₂*X₂-0.1330 32*X₃*X₁+0.081444*X₃*X₂-0.105576*X₃*X₃Obtains through analyzing the optimum response condition was optimized: concentration of 85%, solid-liquid ratio of 47: 1 and extraction time of 42min.The correspondence's response value is 4.362mg/g, obtains the model forecast value confidence level through the verification test to be high.(5) The limonoid were extracted by two hydrotropes such as sodium salicylate (Na-Sal) and sodium cumene sulphonate (Na-CuS) under the same conditions.The study showed it was more effective of using Na-CuS that the maximum limonoid yield of 4.023 mg/g seeds was obtained.(6) The best conditions for the extraction techniques of limonoids by Na-CuS in single factor experiments were:, the concentration of extraction agent was 2mol/L, 6 hours,temperature was 40℃, the volume of extraction agent was 20mL. (7) The best conditions for the extraction techniques of limonoids by Na-CuS in orthogonal experiments were:the concentration of extraction agent was 2.5mol/L , 6 hours , temperature was 40℃, the volume of extraction agent was 25mL.The significance of influencing factor is the concentration of extraction agent > the volume of extraction agent > temperature >time.The obtain rate of limonoids in the best conditions is 4.332mg/g.(8) Absorption specialities of AB-8,HZ-841,DM130,D3520,XAD-16 macropore resin to limonoids were studied. The XAD-16 resin was the best in integrated estimate.the adsorption rate of XAD-16 resin was 94.12%, the adsorption quantity was 43.58 mg/g, the elution rate was 85.36%.(9) The technological process to purify limonoids by XAD-16 macropore resin method were: 2.315mg/mL was the adsorptive concentration, 0.5mL/min was the Sample velocity; 80% alcohol as the desorption solution, the velocity was 0.5mL/min,the same as the desorption velocity, the volume of desorption solution was 200mL.