Table 2.
Absorption maxima in acetone or petroleum ether, number of conjugated double bonds (c.d.b.) and colour of carotenoids important for skin health and appearance [99,100].
| Carotenoid | Colour | c.d.b. (in rings) | Absorption maxima (nm) | ||
|---|---|---|---|---|---|
| Canthaxanthin | Red | 13 (4) | 472 | ||
| Astaxanthin * | Red | 13 (4) | 468 | ||
| Lycopene | Red | 11 (0) | 446 | 474 | 504 |
| β-Carotene | Orange | 11 (2) | 454 | 480 | |
| Zeaxanthin | Orange | 11 (2) | 454 | 480 | |
| Lutein | Yellow | 10 (1) | 424 | 448 | 476 |
| Phytofluene * | Colourless | 5 (0) | 331 | 348 | 367 |
| Phytoene * | Colourless | 3 (0) | 286 | ||
* Absorption maxima in petroleum ether.