Annatto pigment production in root cultures of Achiote (Bixa orellana L.).

Bixa orellana L. is a tree native to South
America known for its reddish orange pigment ‘annatto’
produced only on the aril portion of its seeds. It is the most
preferred natural food colorant next to saffron, having wide
applications in the dairy industry and also as a cosmeceutical.
Normal root cultures of B. orellana were established
under in vitro conditions on Murashige and Skoog (MS)
medium containing a-naphthaleneacetic acid (NAA),
indole-3-butyric acid (IBA) and indole-3-acetic acid (IAA)
at 0.05–0.2 mg l-1. The annatto pigment from in vitroraised
normal roots was extracted with chloroform, and
later the ethanol-dissolved extract was analyzed both
qualitatively by thin-layer chromatography (TLC) and
spectrophotometrically quantified followed by High Performance
Liquid Chromatography (HPLC) confirmation.
The maximum amount of annatto pigment (346 ± 3.8 mg/
100 g dry wt.) and maximum root biomass (152 ± 2.5 mg
dry wt.) were recorded after 45 and 60 days of growth,
respectively, on MS medium containing 0.1 mg l-1 indole-
3-butyric acid (IBA). Producing annatto pigment from
normal root cultures under in vitro conditions is a novel
approach when compared to the natural annatto pigment
that is produced only on the aril portion of seeds. This
allows the production of fresh pigment throughout the year.