Abstract: In this study, the functional and flavor components in antihypertensive Zijuan Pu-erh tea and bitter Kuding tea, which can be added to whole buckwheat tea to compensate their deficiency, were extracted by microwave-assisted organic solvent extraction. The results showed that Zijuan Pu-erh tea samples stored for different times exhibited a significant difference in all investigated functional components except theaflavins (P＜0.05). Nutritional ingredients significantly differed among young leaf Kuding tea, old leaf Kuding tea and their superfine powders (P＜0.05). Orthogonal array based optimizations showed that the optimum extraction conditions of Zijuan Pu-erh tea were 65% ethanol concentration, 540 W microwave output power, 50 s extraction time and 10:1 liquid-to-solid ratio and the resulting extract was rich in anthocyanins (δA = 0.925) and contained 27.709% polyphenol, 0.707% theaflavins (TF), 15% thearubigins(TR), 259.735 mg/g total catechinsand 7.053% caffeine. The optimum extraction conditions of Kuding tea were 55% ethanol concentration, 360 W microwave output power, 120 s extraction time and 25:1 liquid-to-solid ratio, and the extract obtained under the optimum conditions tasted strongly bitter and contained 30.79% flavonidos, 0.699 mg/g chlorophyll, 13.619% tea polyphenol, 4.812% caffeine, and 26.161 mg/g total catechins. Together, these findings demonstrate that both tea extracts can be used to enhance the flavor and function of buckwheat tea.

Key words: buckwheat, Zijuan Pu-erh tea, Kuding tea, functional components