New Bixin Sources for Natural Colors?

VELLORE, IndiaAs interest in natural colors grows, researchers in India are investigating ways to enhance plants content of bixin, a naturally occurring carotenoid pigment that is one of the major coloring compounds found in annatto.

Annatto is orange-red colorant obtained through extraction of the seeds of the Bixa orellana tree and is widely used in the food industry. Annatto seeds contain 4.55 to 5.5% pigments, of which 70% to 80% is bixin.

Recent research has pinpointed the biosynthetic pathway of bixin and found that three genes from B. orellana govern bixin synthesis from its precursor, lycopene. The genes in the plant code for molecules that catalyze the sequential conversion of lycopene into bixin. Scientists have previously done comparative genome sequence analysis based on available chemical data and by analogy to biosynthetic pathway for bixin.

The researchers have identified and functionally characterized that bixin coding genes are not only present in B. orellana, but also in Crocus sativus (saffron crocus) and Vitis vinefera (grape). They suggest that Crocus and Vitis could be alternative and competitive sources for natural bixin production for the natural-color industry.