Table 2.
Dose-over-threshold (DOT) of bitterness substances in black tea, oolong tea, and green tea soups.
Tastant | Threshold (μmol/L) | Black tea soup | Oolong tea soup | Green tea soup | ||||||
---|---|---|---|---|---|---|---|---|---|---|
Dian | Qimen | Hainan | Dahongpao | Anxi | Rougui | Longjing | Maojian | Biluochun | ||
TSA | 65 | 2.88 ± 0.09 a | 1.47 ± 0.05 b | 0.99 ± 0.05 c | 0.83 ± 0.00 d | 0.08 ± 0.00 e | 0.07 ± 0.00 e | ND | ND | ND |
C | 860 | ND | ND | ND | 0.01 ± 0.00 c | ND | 0.01 ± 0.00 c | 0.02 ± 0.00 b | 0.02 ± 0.00 b | 0.03 ± 0.00 a |
EC | 930 | ND | 0.01 ± 0.00 d | ND | ND | 0.01 ± 0.00 d | 0.01 ± 0.00 d | 0.08 ± 0.00 b | 0.09 ± 0.00 a | 0.04 ± 0.00 c |
EGCG | 190 | 0.06 ± 0.00 f | 0.05 ± 0.00 g | 0.05 ± 0.00 g | 0.23 ± 0.01 c | 0.09 ± 0.00 e | 0.11 ± 0.00 d | 0.64 ± 0.03 b | 0.68 ± 0.00 b | 1.06 ± 0.00 a |
GCG | 390 | ND | ND | ND | ND | ND | ND | 0.03 ± 0.00 b | 0.03 ± 0.00 b | 0.17 ± 0.00 a |
ECG | 180 | 0.06 ± 0.00 d | 0.01 ± 0.00 g | 0.03 ± 0.00 e | 0.06 ± 0.00 d | 0.02 ± 0.00 f | 0.02 ± 0.00 f | 0.57 ± 0.02 a | 0.52 ± 0.00 b | 0.47 ± 0.00 c |
CG | 170 | 0.01 ± 0.00 a | 0.01 ± 0.00 a | 0.01 ± 0.00 a | 0.01 ± 0.00 a | ND | ND | ND | ND | ND |
Caffeine | 500 | 0.39 ± 0.01 b | 0.29 ± 0.01 c | 0.26 ± 0.01 c | 0.19 ± 0.00 d | 0.06 ± 0.00 e | 0.06 ± 0.00 e | 0.36 ± 0.01 b | 0.35 ± 0.00 b | 0.48 ± 0.00 a |
Different letters in the same column indicate significant differences between mean values (p < 0.05). ND means that the substance is not detected. The bitterness threshold of C, EC, EGCG, GCG, ECG, CG, and caffeine was cited from Xu et al. (8).