减压内部沸腾法提取银杏总黄酮的工艺研究

目的]研究银杏叶中银杏总黄酮的提取方法。方法]采用减压内部沸腾法,对银杏叶粉末进行解吸和提取,考察了解吸和提取中各因素对提取率的影响,优选出最佳解吸和提取条件,并与传统提取方法进行比较。结果]优选的最佳解吸条件为:解吸剂为浓度80%乙醇,解吸时间20 min,解吸剂用量15 ml;最佳提取工艺为:提取压力为0.067 MPa,提取温度为60℃,提取剂为浓度30%乙醇,提取2次,每次5 min;在此条件下,银杏总黄酮的提取提取率为2.55%。与传统的乙醇提取方法比较,温度降低了20℃,提取速度快了11倍,乙醇用量减少了2倍,提取液色素、杂质含量少,并可以直接上柱,银杏总黄酮的纯度达29.8%,具有明显的优势。结论]该方法节约、快速、有效,可用于银杏叶中银杏总黄酮的提取。

Extraction of Total Flavonoids from Ginkgo biloba by Decompressing Inner Ebullition

Objective] To study the extraction methods of total flavonoids from Ginkgo biloba leaves. Method] By using the decompressing inner ebullition, the Ginkgo biloba leaves powder was desorbed and extracted to investigate the effects of each factor on the extraction rate, the best desorption and extraction conditions were found out, and then compared with traditional extraction method. Result] The optimal desorption conditions were: with 80% ethanol as the desorption solvent, 20 min desorption time and 15 ml solvent dose; the best extraction technology was 0.067 MPa extraction pressure, 60 ℃ extraction temperature, 30% ethanol as extraction solvent, twice of extraction, 5 min each time; under these conditions, the extraction rate of flavonoids could reach up to 2.55%. Compared with the traditional ethanol extraction method, the temperature was cut down by 20 ℃, the extraction was 12 times faster, ethanol dose was three times less, the extraction solution had little pigment and impurities, and could be purified with macroporous adsorbing resin directly, the purity of total flavonoids from Ginkgo biloba was 29.8%, the advantages were obvious. Conclusion] The method was economical, rapid and efficient, therefore could be applied to the extractin of flavonoids from Ginkgo biloba leaves.