Table 2.
Digestive stability and bioaccessibility of phenolics found in the different EP plant parts extracts.
| Peak | Compound | EL (Undigested) | EL (Digested) | B (%) | EF (Undigested) | EF (Digested) | B (%) | ER (Undigested) | ER (Digested) | B (%) |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Caftaric acid | 2.66 ± 0.17 *a | 0.28 ± 0.12 b | 10 ± 4 | 0.56 ± 0.08 c | 0.13 ± 0.04 d | 23 ± 5 | 0.45 ± 0.02 c | 0.18 ± 0.008 b,d | 39 ± 2 |
| 2 | Chlorogenic acid | 0.07 ± 0.009 | 0.07 ± 0.03 | 98 ± 53 | 0.04 ± 0.02 | 0.05 ± 0.02 | 120 ± 93 | 0.03 ± 0.001 | nd | - |
| 3 | Neochlorogenic acid | nd | nd | - | 0.03 ± 0.006 | 0.05 ± 0.008 | 180 ± 68 | 0.06 ± 0.01 | nd | - |
| 4 | Caffeic acid 1 | 0.31 ± 0.06 a | 0.32 ± 0.03 a,b | 106 ± 13 | 0.03 ± 0.005 c | 0.23 ± 0.01 a | 663 ± 65 | 0.07 ± 0.004 c | nd | - |
| 5 | Chicoric acid 1 | 9.54 ± 0.71 a | 0.42 ± 0.05 b | 4 ± 1 | 4.85 ± 1.07 c | 0.46 ± 0.09 b,d | 10 ± 2 | 7.30 ± 0.51 e | 0.26 ± 0.04 b,d | 3 ± 0.4 |
| 6 | Feruloylcaffeoyltartaric acid 1 | 0.59 ± 0.12 a | 0.58 ± 0.05 a,b | 102 ± 27 | 0.28 ± 0.06 c | 0.10 ± 0.03 d | 36 ± 2 | 0.43 ± 0.03 a,b,c | nd | - |
| 7 | Feruloylcaffeoyltartaric acid 2 | 0.14 ± 0.02 a | nd | - | 0.23 ± 0.05 b | 0.07 ± 0.03 a | 31 ± 7 | 0.52 ± 0.03 c | nd | - |
| Total phenolics | 13.3 ± 1.09 | 1.67 ± 0.28 | 6.02 ± 1.28 | 1.08 ± 0.27 | 8.87 ± 0.61 | 0.43 ± 0.04 | ||||
* Values are the mean of three independent determinations ± standard deviation. The quantification (mg/g extract) of the phenolic compounds in leaves, flowers, and root extracts of EP before and after digestion was quantified at 320 nm with chicoric acid.1 Quantified with the authentical standard; EP, Echinacea purpurea L.; EL, Echinacea purpurea leaves extract; EF, Echinacea purpurea flowers extract; ER, Echinacea purpurea roots extract; B: Bioaccessibility; nd: not detected. Different lowercase letters in the same row indicate significant differences (p < 0.05).