微波辅助萃取苦瓜总皂苷工艺研究

Studies on Extracting of Total Saponins in Bitter Melon by Microwave-assisted Eextractive Method

为优选微波辅助萃取方法,以苦瓜总皂苷含量为考察指标,研究萃取溶剂浓度、萃取温度、料液比、萃取时间等因素对总皂苷含量的影响。通过正交试验确定苦瓜总皂苷萃取的最佳工艺条件为:萃取温度70℃,料液比1∶24,乙醇体积分数60%,萃取12min。此时测得的总皂苷含量为3.532%,优于正交试验的较优组。将微波辅助萃取法与水浴振荡法和超声提取法进行比较,结果表明,微波辅助萃取法不但大大缩短了萃取时间,而且提高了萃取率。对萃取物用化学法、红外光谱法检测,结果其为三萜类皂苷。通过红外光谱检测和HPLC分析,肉桂皂苷是多种同分异构体的混合物。

The microwave-assisted extraction was chosen as the optimum extraction method. The content of the total saponins in Bitter Melon was regarded as the index of investigation. The factors such as the extracting temperature, solid-liquid ratio, ethanol concentration and extracting time that affect the content of total saponins were studied. According to the orthogonal experimental design, the optimum extracting conditions of total saponins in Bitter Melon were showed as followed： extracting temperature was 70℃, solid-liquid ratio was 1：24, ethanol concentration was 60%, extracting time was 12 min. The content of the total saponins was 3.532%, which was superior to the result of optimum group of orthogonal experiment. Compared with the water bath shaking and ultrasonic-assisted extraction, the not only did microwaveassisted extraction shortened the extracting time greatly, but also improved the extracting efficiency. Then Chemical Method and Infrared Spectrum Method were made to identify the type of extracting products. The results showed that the total saponins in Bitter Mellon were triterpene saponins. It was tested that the total saponins in cinnamon were a mixture which contained several isomeric compounds by Infrared Spectrum Method and HPLC.