Table 5.
Concentration of bioelements and toxic metals in Pu-erh (loose/bags) and fruit tea (bags) samples in milligrams/100 g w.w. (±SD, range) and an average percentage of leaching (%)
| Elements | Pu-erh loose form (China) | Pu-erh tea bags (marketed) | Fruit tea (tea bags) | Black tea with fruit (tea bags) |
|---|---|---|---|---|
| n | 12 × 6 | 5 × 6 | 7 × 6 | 8 × 6 |
| Ca | 872 ± 352 (325–1437) 15.9 ± 19.7 % |
657 ± 144 (457–845) 9.90 ± 6.71 % |
727 ± 154 (531–978) 42.9 ± 11.4 % |
632 ± 318 (120–1020) 25.3 ± 19.1 % |
| K | 2653 ± 186 (2386–3085) 56.9 ± 19.7 % |
2457 ± 454 (1742–3141) 46.7 ± 19.1 % |
1113 ± 555 (410–2167) 76.5 ± 8.86 % |
1275 ± 137 (1008–1467) 68.4 ± 17.5 % |
| Mg | 322 ± 49.2 (271–397) 17.8 ± 7.35 % |
307 ± 45.0 (242–379) 25.4 ± 3.88 % |
193 ± 88.8 (90.1–336) 55.0 ± 20.2 % |
118 ± 26.0 (79.6–151) 56.6 ± 4.69 % |
| Na | 16.2 ± 5.40 (10.0–27.6) 40.6 ± 13.1 % |
27.1 ± 13.1 (15.0–50.6) 45.3 ± 18.9 % |
11.8 ± 4.73 (4.11–18.4) 67.7 ± 24.8 % |
8.32 ± 5.08 (3.89–17.6) 56.9 ± 23.2 % |
| P | 1421 ± 180 (1261–1940) 26.6 ± 2.21 % |
1356 ± 208 (948–1526) 23.6 ± 1.10 % |
519 ± 134 (334–781) 15.0 ± 3.50 % |
881 ± 64.0 (778–979) 14.5 ± 1.67 % |
| Mn | 77.2 ± 12.0 (47.3–94.2) 15.7 ± 3.42 % |
76.6 ± 10.4 (56.7–84.9) 15.8 ± 3.04 % |
21.7 ± 5.82 (13.0–30.0) 56.2 ± 8.28 % |
76.2 ± 27.6 (34.0–115) 19.5 ± 6.94 % |
| Fe | 32.2 ± 5.81 (16.8–41.6) 2.37 ± 0.71 % |
68.3 ± 10.2 (50.9–78.3) 1.65 ± 0.36 % |
33.7 ± 10.7 (18.2–50.2) 2.64 ± 1.07 % |
21.8 ± 6.93 (14.0–35.4) 0.91 ± 0.55 % |
| Zn | 3.84 ± 0.42 (3.38–4.73) 29.1 ± 12.6 % |
3.77 ± 0.68 (2.45–4.43) 32.2 ± 7.73 % |
2.04 ± 0.52 (1.47–3.00) 46.0 ± 17.0 % |
2.6 ± 0.53 (1.95–3.60) 39.2 ± 13.9 % |
| Cu | 1.93 ± 0.17 (1.66–2.21) 5.15 ± 3.98 % |
1.94 ± 0.38 (1.27–2.44) 11.6 ± 2.00 % |
0.47 ± 0.10 (0.38–0.65) 31.9 ± 7.95 % |
1.1 ± 0.81 (0.14–2.72) 43.1 ± 27.3 % |
| Co | 0.02 ± 0.005 (0.01–0.03) 3.76 ± 1.47 % |
0.03 ± 0.006 (0.02–0.04) 3.81 ± 0.35 % |
0.02 ± 0.01 (0.01–0.04) 3.62 ± 2.69 % |
0.04 ± 0.02 (0.02–0.06) 2.12 ± 1.31 % |
| Cd | 0.02 ± 0.001 (0.02–0.02) 4.67 ± 2.44 % |
0.02 ± 0.001 (0.02–0.02) 2.80 ± 1.40 % |
0.02 ± 0.003 (0.02–0.03) 8.24 ± 4.29 % |
0.02 ± 0.001 (0.02–0.02) 5.18 ± 1.73 % |
| Cr | 0.15 ± 0.03 (0.09–0.19) 45.6 ± 15.4 % |
0.33 ± 0.04 (0.28–0.38) 20.0 ± 2.78 % |
0.24 ± 0.09 (0.09–0.41) 40.4 ± 30.2 % |
0.22 ± 0.13 (0.08–0.48) 29.2 ± 7.70 % |
| Ni | 0.60 ± 0.06 (0.49–0.71) 34.3 ± 17.1 % |
0.52 ± 0.08 (0.36–0.60) 45.3 ± 2.86 % |
0.19 ± 0.04 (0.12–0.25) 42.6 ± 14.2 % |
0.46 ± 0.09 (0.35–0.57) 66.8 ± 11.7 % |
| Pb | 0.04 ± 0.02 (<LOD–0.08) 37.2 ± 22.9 % |
0.09 ± 0.03 (0.04–0.13) 15.8 ± 3.28 % |
0.01 ± 0.002 (<LOD–0.03) 43.1 ± 23.0 % |
0.01 ± 0.008 (<LOD–0.02) 43.8 ± 29.5 % |
n number of samples multiplied by number of analytical subsamples
LOD for Pb = 0.004 mg/100 g