Figure 1.
Structures of the main anthocyanin-3-O-glucosides found in bilberry and respective wavelength at the maximum absorption in the visible region (λmax). Note that anthocyanins have characteristic colors, but the color of anthocyanins can change with the pH of the solution [11,20].
| Anthocyanin (% in Content in Bilberry) |
R1 | R2 | λmax (nm) * | |
|---|---|---|---|---|
| R3=H | R3=gluc | |||
| Delphinidin (15.17%) | OH | OH | 546 | 541 |
| Cyanidin (8.36%) | OH | H | 535 | 530 |
| Petunidin (6.64%) | OH | OCH3 | 543 | 540 |
| Malvidin (5.43%) | OCH3 | OCH3 | 542 | 538 |
| Peonidin (1.87%) | OCH3 | H | 532 | 528 |
| * In methanol with 0.01% HCl. | ||||