杀青和初炒对杜仲绿茶中绿原酸和总黄酮的影响

Effect of Fixing and Drying Process on the Chlorogenic Acid and Total Flavonoids Contents in Eucommia Green Tea

采用液相色谱法和分光光度法分别测定了不同杀青方式、不同初炒温度和初炒时间对杜仲绿茶中绿原酸和总黄酮含量的影响。结果表明,杀青后绿原酸和总黄酮含量明显降低,沸水烫漂使绿原酸和总黄酮含量下降最多,其次是烘青和蒸汽杀青,微波杀青效果最好。通过单因素试验和二次通用旋转组合设计试验表明,初炒温度和初炒时间对绿原酸和总黄酮的含量有明显影响。初炒后绿原酸含量下降,总黄酮含量升高,超过200℃后总黄酮含量降低。当初炒时间为9 min,初炒温度为130℃时,绿原酸和总黄酮的质量分数达到最高,分别为1.54%和0.58%。

The effect of different fixing methods, drying temperature and duration on the content of chlorogenic acid and flavonoids in Eucommia green tea were measured using high-performance liquid chromatography and spectrophotometry respectively. The results show that chlorogenic acid and total flavonoid content decrease significantly after fixing. Microwave fixing was the best fixing mode, next came the dry fixing and steam fixing, and the largest decline of the activity contents was caused by blanching of boiling water. The optimum microwave fixing conditions were 800 W and lmin. The single factor and quadratic general rotation design experiments suggested that roast temperature and duration affect the active ingredient obviously. After drying, the chlorogenic acid content decrease, and the total flavonoid content increase, but total flavonoid content decrease when the temperature exceeds 200℃. When the duration of drying was 9 minutes and the temperature was 130℃, the content of chlorogenic acid and the flavonoid reached maximum of 1.54 % and 0.58 % respectively.