Table 5.
Comparative analysis of phenolic acids levels in six different types of teas (n = 121), including gallic acid (GA), chlorogenic acid (CHL), ρ-coumaric acid (COU), ferulic acid (FER), sinapic acid (SIN), and caffeic acid (CAA).
| Phenolic Acids | GT (n = 29) | YT (n = 7) | DT (n = 14) | WT (n = 12) | OT (n = 42) | BT (n = 17) | F Value | p Value |
|---|---|---|---|---|---|---|---|---|
| Gallic acid | 0.99 ± 0.52 (0.28–2.51) |
1.20 ± 0.66 (0.39–2.03) |
4.12 ± 2.89 (1.03–11.57) a, b |
2.24 ± 0.87 (0.9–3.61) a, c |
1.12 ± 0.94 (0.07–3.71) c |
2.54 ± 0.91 (1.23–5.04) a, c, e |
16.62 | 0.000 |
| Percentage of total phenolic acids | 24.59% | 21.95% | 92.72% | 10.12% | 46.18% | 38.70% | ||
| Chlorogenic acid | 1.50 ± 4.60 (0–22.83) |
3.28 ± 2.61 (0.1–7.88) |
0.01 ± 0.03 (0–0.09) |
19.25 ± 34.50 (0–80.76) |
0.15 ± 0.24 (0–1.29) d |
2.79 ± 11.19 (0–46.2) |
5.352 | 0.000 |
| Percentage of total phenolic acids | 37.10% | 59.93% | 0.29% | 86.79% | 6.26% | 42.42% | ||
| ρ-coumaric acid | 0.15 ± 0.13 (0–0.46) |
0.09 ± 0.11 (0.01–0.32) |
0.08 ± 0.18 (0–0.66) |
0.12 ± 0.18 (0–0.63) |
0.14 ± 0.32 (0–1.64) |
0.80 ± 1.64 (0.03–4.97) |
3.179 | 0.010 |
| Percentage of total flavonols | 3.82% | 1.55% | 1.70% | 0.54% | 5.63% | 12.23% | ||
| Ferulic acid | 1.05 ± 2.93 (0–15.05) |
0.24 ± 0.35 (0.02–1.02) |
0.06 ± 0.05 (0.01–0.18) |
0.33 ± 0.34 (0.02–0.96) |
0.64 ± 0.52 (0–1.62) |
0.13 ± 0.13 (0–0.39) |
1.358 | 0.245 |
| Percentage of total phenolic acids | 26.16% | 4.45% | 1.32% | 1.47% | 26.41% | 1.93% | ||
| Sinapic acid | 0.34 ± 0.31 (0.03–1.34) |
0.66 ± 0.83 (0.2–2.5) |
0.18 ± 0.11 (0.04–0.4) |
0.24 ± 0.28 (0–0.88) |
0.37 ± 0.36 (0–1.32) |
0.31 ± 0.46 (0.02–1.88) |
1.741 | 0.131 |
| Percentage of total phenolic acids | 8.34% | 12.12% | 3.96% | 1.08% | 15.52% | 4.72% | ||
| Caffeic acid | nd | nd | nd | nd | nd | nd |
Tea type: OT, oolong tea; GT, green tea; WT, white tea; DT, dark tea; YT, yellow tea. Note: Data expressed as mean ± standard deviation and range (min-max). a, b, c, d, e Values with different letters indicate significant differences (p < 0.05) compared to GT, YT, DT, WT, and OT samples using ANOVA and Tukey post hoc test. The results were reported in mg/g to indicate the concentration of compounds in 1 g of tea leaves after conversion.