Photobleaching of anthocyanins using tunable dye laser

Abstract

The flowers of Hibiscus sabdarifa were extracted with acidified methanol. The Anthocyanin of Hibiscus sabdarifa was obtained as red needles from absolute ethanol. A dye laser operating at 520 nm was used to bleach the red- colored anthocyanin. A mixture of the anthocyanin and triethylamine was irradiated with laser for 40 minutes. Under such conditions the iv ‫‪The anthocyanin then oxidizes triethylamine and reduces to a colourless‬‬ ‫.‪radical‬‬ ‫‪AS‬‬ ‫1‬ ‫*‪AS‬‬ ‫3‬ ‫‪hν‬‬ ‫0‪AS‬‬ ‫1*‬ ‫)‪(Red‬‬ ‫3*‪AS• + •NR‬‬ ‫3‬ ‫3‪AS* +:NR‬‬ ‫)‪(Colourless‬‬ ‫‬