Stability Study of the Pigment Extract from a Wild <i>Pycnoporus sanguineus</i>

The stability of crude pigment of Pycnoporus sanguineus strain 28cc under different conditions was assessed. The strain was isolated from the fruit body of the fungus collected in Fenglin National Nature Reserves (China) and had been identified by morphological and rDNA-ITS based approach. The natural pigments were obtained from cultural liquid of submerged culture by adsorption of macro-porous resin (HPD-722) and eluted with 80% ethanol. The natural colorants had a characteristic absorption peak of 416nm (corresponds cinnabarine) used for determination of pigment stability. P. sanguineus pigment tolerant to high temperatures and could keep stability during pasteurization temperature. It had orange-red colors in both acidic and alkaline environment, as well as exhibits good stability at pH 4-7. In the alkaline environment, pigments showed increased in absorbance and deepness in color. P. sanguineus pigments could toleranted to various metal ions (K⁺, Na⁺, Cu²⁺, Zn²⁺ or Al³⁺) and displayed strong stability to reductant, but oxidant result in a certain degree of fading. The result from this study indicated that P. sanguineus pigment displayed good stability under various conditions, which is the basis of their market potential. The obtained characteristics of pigment stability of this strain can be used for development of production of natural pigment.