绿咖啡豆中低咖啡因绿原酸的提取分离研究

Extraction Technology of Chlorogenic Acid with Low Caffeine in Coffee Beans

建立高效液相色谱—双波长同时检测咖啡豆提取物中绿原酸和咖啡因含量的方法。咖啡因和绿原酸在0.2～1.0 mg·mL^(-1)范围内,峰面积与浓度呈现良好的线性关系。咖啡因:Y=44077X+227.78,R=0.9997,RSD=0.78%;绿原酸:Y=34896X+289.96,R=0.9995,RSD=0.93%。以绿原酸含量为指标,在单因素试验基础上建立正交试验,确定从绿咖啡豆中提取绿原酸的最佳条件为乙醇浓度20%,液料比6∶1,提取时间60 min,提取温度70℃。以咖啡因和绿原酸含量为指标,通过萃取试验,确定最佳脱咖啡因萃取剂为环己烷-三氯甲烷-丙酮混合溶剂,萃取工艺为1.5倍体积萃取剂萃取3次,产物中咖啡因含量由(3.52±0.08)%下降至(0.47±0.11)%。

The method of high performance liquid chromatography with dual wavelength was established for simultaneous determination of caffeine and chlorogenic acid in coffee bean extracts.The result showed a good linear relationship between peak area and concentration in the range of 0.2-1.0 mg·mL^-1.The regression equations of caffeine were:Y=44077X+227.78,R=0.9997,RSD=0.78%;the regression equations of chlorogenic acid were:Y=34896X+289.96,R=0.9995,RSD=0.93%.With chlorogenic acid content as indicator,the optimal conditions for extracting chlorogenic acid from green coffee beans were determined as follows:ethanol concentration was 20%,solid-liquid ratio was 6:1,extraction time was 60 min,the extraction temperature was 70℃according to orthogonal test and single factor test.Taking caffeine and chlorogenic acid contents as indicators,the best decaffeination extractant was cyclohexane-trichloromethane-acetone mixture,and the extraction process was extracted three times with 1.5 volumes of cyclohexane-trichloromethaneacetone mixture with the caffeine content decreased from(3.52±0.08)%to(0.47±0.11)%.