The aim of this study was to compare methods for efficient extraction of green tea metabolites. Aqueous green tea leaf powder extracts were prepared by ultra-sonication extraction (UE), agitation extraction (AE), and the conventional extraction method (control) at different temperatures (60, 70, and 80 °C) and times (5–30 min). Compared to the control, both UE and AE techniques significantly increased the yields of polyphenols (three-fold), catechins (two-fold), and flavonoids (two-fold), and resulted in higher antioxidant activity. For both techniques, highest extraction efficiency of bioactive metabolites occurred at 80 °C for 20 min. Caffeine, total free amino acid, vitamin C, and total soluble solid contents were also significantly increased using either technique compared to the control. Thus, AE and UE have similar extraction efficiencies and could be used to prepare antioxidant-rich green tea extract or green tea extract powder.

这项研究的目的是比较有效提取绿茶代谢产物的方法。通过超声提取（UE），搅拌提取（AE）和常规提取方法（对照）在不同温度（60、70和80°C）和时间（5–30）下制备绿茶叶粉提取物分钟）。与对照相比，UE和AE技术均显着提高了多酚（三倍），儿茶素（两倍）和类黄酮（两倍）的产量，并导致了更高的抗氧化活性。对于这两种技术，生物活性代谢物的最高提取效率均在80°C下进行20分钟。使用咖啡因，总游离氨基酸，维生素C和总可溶性固形物含量，与对照组相比，都可以显着提高。因此，