Table 1.
λmax (nm) and % absorbance retention, defined as absorbance at respective λmax in pHn/absorbance in pH1 × 100, of delphinidin (Dp) and petunidin (Pt) derivatives in pH 1–9, n = 3 (standard deviation in parenthesis). Different superscript letters indicate significant differences (p < 0.05) between derivatives of the same anthocyanidin in the same pH.
| Anthocyanin | pH 1 | pH 2 | pH 3 | pH 4 | pH 5 | pH 6 | pH 7 | pH 8 | pH 9 |
|---|---|---|---|---|---|---|---|---|---|
| λmax (nm) | |||||||||
| Dp-3-rut-5-glu | 517 c (0) | 518 c (0) | 518 c (2) | 521 c (0) | 522 c (4) | 450 c (1) | 583 b (0) | 603 c (1) | 600 b (1) |
| Dp-3-cis-p -cou-rut-5-glu | 528 a (1) | 528 a (1) | 529 a (1) | 534 a (2) | 617 a (1) | 630 a (1) | 632 a (0) | 631 a (1) | 632 a (1) |
| Dp-3-trans-pcou-rut-5-glu | 521 b (1) | 523 b (0) | 523 b (1) | 531 b (1) | 563 b (2) | 576 b (1) | 566 c (0) | 608 b (2) | 584 c (4) |
| Pt-3-rut-5-glu | 518 c (0) | 519 c (0) | 521 c (2) | 519 b (6) | 522 b (9) | 524 c (2) | 589 b (1) | 610 b (1) | 604 b (1) |
| Pt-3-cis-p-cou-rut-5-glu | 531 a (0) | 531 a (0) | 532 a (1) | 534 a (0) | 553 a (6) | 564 a (1) | 621 a (1) | 627 a (0) | 630 a (1) |
| Pt-3-trans-p-cou-rut-5-glu | 523 b (0) | 524 b (1) | 525 b (2) | 535 a (4) | 535b (2) | 538 b (0) | 559 c (0) | 579 c (0) | 578 c (0) |
| % absorbance retention | |||||||||
| Dp-3-rut-5-glu | 53.7 c (2.4) | 13.4 c (0.1) | 4.3 b (0.1) | 3.3 c (0.4) | 3.4 c (0.0) | 20.8 b (0.3) | 45.2 b (1.6) | 35.7 b (4.2) | |
| Dp-3-cis-p-cou-rut-5-glu | 77.0 a (1.1) | 36.3 a (1.2) | 9.0 a (0.3) | 25.6 a (0.8) | 45.8 a (2.5) | 70.6 a (2.2) | 70.6 a (2.3) | 71.1 a (1.3) | |
| Dp-3-trans-pcou-rut-5-glu | 68.2 b (0.7) | 18.6 b (0.2) | 4.1 b (0.1) | 4.9 b (0.2) | 14.3 b (0.2) | 70.5 a (2.4) | 73.5 a (0.2) | 68.4 a (3.0) | |
| Pt-3-rut-5-glu | 55.9 c (2.1) | 11.5 c (0.2) | 3.1 c (0.2) | 2.1 c (0.1) | 3.5 c (0.1) | 34.8 c (4.1) | 71.3 b (4.7) | 78.3 c (3.1) | |
| Pt-3-cis-p-cou-rut-5-glu | 82.0 a (1.8) | 31.8 a (0.4) | 8.3 a (0.3) | 5.1 a (0.1) | 7.9 b (1.0) | 60.4 b (3.3) | 88.3 a (0.6) | 104.4 b (0.7) | |
| Pt-3-trans-p-cou-rut-5-glu | 66.1 b (0.9) | 19.6 b (1.1) | 5.1 b (0.3) | 3.5 b (0.3) | 17.8 a (0.7) | 69.4 a (0.8) | 90.3 a (3.4) | 141.8 a (4.8) | |