Abstract:

Tea-drinking is an ideal way to supplement the trace element selenium (Se) for people. Se contents in the
leaves of 10 cultivars of ancient tea trees for Fenghuang Dancong tea were measured by graphite digestion method, and
Se dissolution characteristics were analyzed during brewing. The results were obtained as follows: 1) the Se contents in
mature and young leaves were 0.056 0–0.352 5 and 0.045 5–0.299 0 mg/kg, with an average of 0.180 9 and 0.154 5 mg/kg,
respectively, showing a 17.46% difference between both leaves; 2) Se contents in the cultivars Songzhong Milanxiang
(0.299 0 mg/kg) and Songzhong Dongfanghong (0.210 2 mg/kg) met the requirement (0.2–4.0 mg/kg) of Se enriched Fenghuang
Dancong tea made from ‘one bud with two or three leaves’; 3) the leaves of Songzhong Milanxiang with the highest Se
content were selected as experimental materials for analyzing Se dissolution characteristics, and it was shown that 95–100 ℃
of brewing temperature and shorter than 5 min of brewing were fit for Fenghuang Dancong tea from the ancient tea tree,
and these tea leaves could be brewed for many times; and 4) the relationship between either brewing temperature, time or
number (x) and Se dissolubility (y) in tea infusion was consistent with linear equation (y = 0.000 4 x − 0.028 3, R2 = 0.939 8),
logarithmic equation (y = 0.006 6lnx + 0.001 1, R2 =0.957 9) and power function equation (y = 0.013 7 x− 0.786 6, R2 = 0.948 6),
respectively. The ancient tea trees for Fenghuang Dancong tea have great potential for the development of Se-enriched tea.

Key words: Fenghuang Dancong, ancient tea tree, Se content, tea infusion, dissolution characteristics