Purification and Characterization of the Pigments from Rhodotorula glutinis DFR-PDY Isolated from Natural Source

Carotenoids from some of the coloured yeasts like Rhodotorula, Phaffia rhodozyma have attracted commercial interest as a natural pigment for foods. Red yeast isolated from the contaminated PDA plate yeast has been found to produce carotenoids. This red was characterized and designated as Rhodotorula glutinis DFR-PDY. The isolated crude pigment from the red yeast Rhodotorula glutinis DFR-PDY was separated by column chromatography and purified by thin layer chromatography (TLC) yielding three major fractions, viz., a yellow, an orange and a red fraction). The absorption spectra of these three fractions were giving the at max 446 nm, 479 nm and 515 nm respectively. These fractions were further purified to homogeneity through high performance liquid chromatography (HPLC) before subjecting to FT-IR and NMR spectral analysis for their structural elucidation. The spectral data of these fractions revealed that the three major fractions are -carotene, torulene and torularhodin respectively. The red yeast pigment is pretty stable when stored in vegetable oils and it can be of use in oil based food products as foods coloured with these pigments are more appealing.