Penetration of metals to coffee infusions, (%)_
| No of coffee | Na | K | Ca | Mg | Fe | Cu | Zn | Al | Ni | Pb | Cd |
|---|---|---|---|---|---|---|---|---|---|---|---|
| R 1a | 47.1 | 85.6 | 29.4 | 62.0 | 5.4 | 3.4 | 24.0 | 28.0 | 55.3 | 6.8 | 21.5 |
| R 2b | 32.9 | 86.4 | 36.8 | 79.8 | 10.0 | 5.1 | 42.6 | 15.4 | 54.4 | 9.4 | 47.6 |
| R 3 | 39.6 | 80.4 | 24.0 | 65.8 | 8.5 | 10.3 | 23.8 | 39.2 | 28.2 | 7.3 | 28.1 |
| R 4 | 35.7 | 82.3 | 27.3 | 45.8 | 4.9 | 6.2 | 22.3 | 24.3 | 13.6 | 3.2 | 23.2 |
| R 5 | 30.2 | 78.1 | 33.7 | 81.8 | 6.9 | 3.7 | 22.6 | 32.6 | 17.9 | 10.3 | 24.9 |
| R 6 | 44.7 | 88.6 | 38.9 | 89.7 | 8.7 | 3.7 | 31.1 | 23.3 | 18.0 | 6.8 | 31.4 |
Concentration of metals in coffee infusions, (μg/100mL)_
| No of coffee | Na | K | Ca | Mg | Fe | Cu | Zn | Al | Ni | Pb | Cd |
|---|---|---|---|---|---|---|---|---|---|---|---|
| R 1a | 57.0 | 86933 | 1277 | 6593 | 11.30 | 2.82 | 6.10 | 4.93 | 0.78 | 0.558 | 0.042 |
| R 2b | 59.8 | 95667 | 1633 | 8463 | 24.50 | 2.62 | 13.17 | 4.63 | 1.63 | 0.357 | 0.059 |
| R 3 | 42.8 | 132333 | 1037 | 6893 | 15.87 | 6.86 | 6.13 | 8.33 | 1.62 | 0.163 | 0.041 |
| R 4 | 25.5 | 103533 | 1233 | 4600 | 8.93 | 2.15 | 5.53 | 5.40 | 0.82 | 0.133 | 0.036 |
| R 5 | 19.6 | 81467 | 1263 | 7380 | 16.13 | 2.70 | 6.67 | 8.43 | 1.04 | 0.192 | 0.061 |
| R 6 | 63.9 | 95267 | 1827 | 8073 | 15.27 | 1.20 | 8.13 | 2.03 | 1.82 | 0.140 | 0.046 |
| Mean | 44.8 | 99200 | 1378 | 7000 | 15.33 | 3.04 | 7.62 | 5.63 | 1.29 | 0.257 | 0.048 |
| SD | ±18.71 | ±17941 | ±292.36 | ±1369.18 | ±5.33 | ±1.95 | ±2.86 | ±2.43 | ±0.46 | ±0.168 | ±0.010 |
| IQR | (29.3) | (12550) | (303.5) | (1231.8) | (3.8) | (0.5) | (1.66) | (2.89) | (0.75) | (0.17) | (0.015) |
Concentration of metals in roasted coffee (μg/g=ppm)_
| No of roasted coffee | Na | K | Ca | Mg | Fe | Cu | Zn | Al | Ni | Pb | Cd |
|---|---|---|---|---|---|---|---|---|---|---|---|
| R 1a | 24.2 | 20300 | 868 | 2127 | 41.8 | 16.5 | 5.07 | 3.53 | 0.72 | 0.0202 | 0.0124 |
| R 2b | 36.3 | 22133 | 888 | 2120 | 49.1 | 10.3 | 6.18 | 6.01 | 0.69 | 0.0131 | 0.0126 |
| R 3 | 21.6 | 32933 | 864 | 2097 | 37.4 | 13.3 | 5.16 | 4.25 | 1.14 | 0.0115 | 0.0111 |
| R 4 | 14.3 | 25167 | 904 | 2007 | 36.2 | 6.9 | 4.96 | 4.44 | 0.71 | 0.0196 | 0.0222 |
| R 5 | 13.0 | 20867 | 750 | 1803 | 46.7 | 14.6 | 5.89 | 5.17 | 0.84 | 0.0215 | 0.0120 |
| R 6 | 28.6 | 21500 | 939 | 1800 | 35.2 | 6.5 | 5.22 | 1.74 | 1.16 | 0.0155 | 0.0135 |
| Mean | 23 | 23817 | 869 | 1992 | 41.1 | 11.4 | 5.41 | 4.19 | 0.88 | 0.0169 | 0.0140 |
| SD | ±8.80 | ±4779.12 | ±64.30 | ±153.91 | ±5.80 | ±4.13 | ±0.50 | ±1.47 | ±0.22 | ±0.0041 | ±0.0041 |
| IQR | (11.4) | (3383) | (35) | (260.3) | (9) | (6.5) | (0.63) | (1.28) | (0.35) | (0.006) | (0.001) |
Concentration of metals in green coffee (μg/g=ppm)_
| No of green coffee | Na | K | Ca | Mg | Fe | Cu | Zn | Al | Ni | Pb | Cd |
|---|---|---|---|---|---|---|---|---|---|---|---|
| G1a | 10.6 | 19583 | 695 | 1733 | 75.1 | 18.5 | 4.04 | 5.65 | 0.44 | 0.1436 | 0.0145 |
| G 2b | 26.6 | 20213 | 882 | 1783 | 45.2 | 9.4 | 3.09 | 2.73 | 0.39 | 0.0084 | 0.0152 |
| Mean | 18.6 | 19898 | 789 | 1758 | 60 | 14 | 3.6 | 4.2 | 0.415 | 0.076 | 0.015 |
| SD | ±11.31 | ±445.48 | ±132.23 | ±35.36 | ±21.14 | ±6.43 | ±0.67 | ±2.06 | ±0.04 | ±0.0956 | ±0.0005 |
| IQR | (8) | (315) | (93.5) | (25) | (14.95) | (4.55) | (0.48) | (1.46) | (0.03) | (0.068) | (0.0004) |
Empirical levels of significance for differences of metals’ concentrations by ANOVA test_
| Metal | G 1a vs. R 1a | G 2b vs. R 2b |
|---|---|---|
| Na | <0.001* | 0.013* |
| K | 0.509 | 0.008* |
| Ca | <0.001* | 0.802 |
| Mg | 0.050 | 0.003* |
| Fe | 0.004 | 0.427 |
| Cu | 0.335 | 0.235 |
| Zn | 0.017* | 0.007* |
| Al | 0.004* | 0.0066* |
| Ni | 0.020* | 0.012* |
| Pb | <0.001* | 0.030* |
| Cd | 0.173 | 0.135 |