Table 2.
Content of phenolic compounds (mg kg−1, D.W.) determined by HPLC-MS/MS in control and PAW treated rocket samples processed at different times.
| Class | Compound | Treatment Condition (Time) | ||||
|---|---|---|---|---|---|---|
| Control | PAW-2 | PAW-5 | PAW-10 | PAW-20 | ||
| Ellagic acid | 26.2 ± 7.8 a | 32.0 ± 1.6 a | 23.0 ± 5.2 a | 27.2 ± 4.6 a | 23.6 ± 2.5 a | |
| Phenolic acids | Chlorogenic acid | 4.9 ± 0.7 a | 7.7 ± 0.5 b | 5.6 ± 0.1 a | 9.4 ± 0.4 c | 4.8 ± 0.1 a |
| 3,5-Dicaffeoylquinic acid | 3.6 ± 0.2 a | 2.0 ± 0.2 b | 1.1 ± 0.2 c | 1.1 ± 0.2 c | 0.8 ± 0.2 c | |
| 4-Hydroxy benzoic acid | 1.9 ± 0.0 a | 1.0 ± 0.0 b | 1.2 ± 0.0 b | 1.7 ± 0.1 a | 1.7 ± 0.2 a | |
| Ferulic acid | 1.7 ± 0.2 a | 1.5 ± 0.2 a | 1.9 ± 0.2 a | 1.4 ± 0.2 a | 3.8 ± 0.3 b | |
| Caffeic acid | 0.4 ± 0.0 a | 0.3 ± 0.0 a | 0.3 ± 0.0 a | 0.3 ± 0.0 a | 0.9 ± 0.1 b | |
| P- Coumaric acid | 0.3 ± 0.0 a | 0.3 ± 0.1 a | 0.6 ± 0.1 a | 0.6 ± 0.1 a | 0.8 ± 0.0 b | |
| Flavonol aglycons | Quercetin | 11.4 ± 3.4 a | 9.3 ± 2.1 a | 16.6 ± 2.7 ab | 9.9 ± 0.6 a | 20.5 ± 0.9 b |
| Isorhamnetin | 10.5 ± 0.9 ab | 6.3 ± 0.9 bc | 13.5 ± 1.0 a | 3.7 ± 0.0 c | 9.5 ± 1.8 ab | |
| Kaempferol | 0.7 ± 0.1 ab | 0.4 ± 0.0 a | 1.2 ± 0.2 c | 0.4 ± 0.0 a | 1.0 ± 0.1 bc | |
| Flavonol glycosides | Quercetin-3-O-galactoside | 37.0 ± 2.9 a | 43.0 ± 0.8 ab | 52.5 ± 0.4 ab | 50.6 ± 0.5 ab | 58.7 ± 6.7 b |
| Quercetin -3-O-glucoside | 26.4 ± 4.7 a | 32.2 ± 0.3 a | 32.7 ± 6.0 a | 31.9 ± 1.4 a | 33.6 ± 5.7 a | |
| Quercetin-3-O-rutinoside | 2.7 ± 0.0 a | 2.5 ± 0.2 a | 1.0 ± 0.2 b | 0.6 ± 0.0 b | 0.9 ± 0.0 b | |
| Quercetin-3-O-rhamnoside | 1.8 ± 0.3 a | 1.9 ± 0.2 a | 1.0 ± 0.2 b | 0.8 ± 0.2 b | 0.7 ± 0.0 b | |
| Kaempferol-3-O-glucoside | 4.6 ± 0.1 a | 5.1 ± 0.7 ab | 9.3 ± 2.3 bc | 6.2 ± 0.3 abc | 9.8 ± 0.5 c | |
| Flavanone glycoside | Hesperidin | 3.0 ± 0.3 ab | 2.3 ± 0.1 a | 4.9 ± 1.3 b | 3.8 ± 0.1 ab | 4.0 ± 0.1 ab |
| Dihydro- chalcones | Phloretin | 0.3 ± 0.0 a | 0.1 ± 0.0 b | 0.1 ± 0.0 b | 0.1 ± 0.0 b | 0.1 ± 0.0 b |
| Phlorizin | 1.6 ± 0.0 a | 1.8 ± 0.0 ab | 1.9 ± 0.1 b | 2.0 ± 0.1 b | 1.2 ± 0.1 c | |
| Total phenolics | 138.8 ± 13.3 a | 149.7 ± 1.8 a | 168.5 ± 9.6 a | 151.7 ± 10.3 a | 176.4 ± 18.1 a | |
All the data are expressed as mean ± standard deviations. Means that do not share letters in each row differ significantly (p < 0.05) according to Tukey’s test. Legends: PAW-2, PAW-5, PAW-10, and PAW-20 refer to rocket samples subjected to plasma-activated water (PAW) treatment for 2, 5, 10, and 20 min, respectively.