【摘要】 乙醇作溶剂从茶叶中提取咖啡因,以咖啡因产率为评价指标,采用先超声、后采用浸提提取工艺,考察乙醇体积分数、料(茶叶)液(乙醇)比、超声频率、超声时间、后浸提温度和后浸提时间影响。结果表明:在乙醇体积分数95%,料液比1∶12,超声频率25.00 kHz,超声时间10 min,后浸提温度70℃,后浸提时间100 min时,得到产率为34.81%、熔点为236℃的白色针状晶体。更多还原

【Abstract】 With caffeine yield as index and ethanol as solvent extraction of caffeine from tea,first using ultrasound,then extracting technology,effect of ethanol volume fraction,the ratio of solid(tea)to solution(ethanol),ultrasonic frequency,ultrasonic time,post-extraction temperature and post-extractiontime were studied.The white needle crystal caffeine with 34.81% yield,melting point of 236 ℃ was obtained under the conditions of ethanol volume fraction 95%,solid-liquid ratio 1 ∶12,ultrasonic frequency 25.00 kHz,ultrasonic time 10 min,post-extraction temperature 70 ℃ and post-extraction time 100 min.更多还原