Table 2.
Qualitative analysis of the extracts obtained by different methods.
| Peak | Compound | tR (min) | m/z | % Relative Area | |||
|---|---|---|---|---|---|---|---|
| LEA-M | LEA-WB | SFE | PLE | ||||
| 1 | Catechin | 0.770 | 289.1659 | 15.78 | 1.12 | 6.40 | 1.93 |
| 2 | Chlorogenic acid | 0.779 | 353.1818 | 0.29 | 1.56 | 13.52 | 16.28 |
| 3 | Ferulic acid | 0.802 | 193.0495 | 1.66 | 1.84 | 4.41 | 6.90 |
| 4 | Gallic acid * | 3.693 | 169.1064 | 0.10 | 0.14 | 1.97 | 0.15 |
| 5 | Synrigic acid | 3.806 | 197.9050 | 38.65 | 8.44 | 11.85 | 25.04 |
| 6 | Myricetin-3-O-glucoside * | 4.295 | 479.1749 | 2.25 | 0.84 | 2.87 | 5.20 |
| 7 | p-Coumaric acid | 4.343 | 163.1147 | 0.46 | 1.85 | 0.29 | 0.93 |
| 8 | Rutin hydrate | 4.642 | 609.2362 | 1.07 | 39.40 | 9.25 | 9.22 |
| 9 | Myricetin | 5.515 | 317.1280 | 18.06 | 3.35 | 4.92 | 4.54 |
| 10 | Quercetin | 6.229 | 301.1333 | 7.51 | 1.56 | 2.61 | 2.25 |
| 11 | Kaempferol | 7.311 | 285.1339 | 7.08 | 1.51 | 3.15 | 4.05 |
| − | Others | − | − | 7.09 | 38.39 | 38.75 | 23.50 |
LEA-M: Leaching extraction of manually husked bean coat, LEA-WB: Leaching extraction of whole black bean, SFE: Supercritical fluid extraction, PLE: Pressurized liquid extraction. Results are expressed as percentages of the total area, representing the relative abundance of one specific peak related to the sum of the areas of all peaks in the chromatogram for each extraction method. −: non-identified compounds, the percentages were summed and related to the sum of all peaks in the chromatogram. m/z values are related to negative ionization. Compounds with * symbol were identified only with m/z values, while compounds without the symbol were identified with m/z values and pure standards.