Study on the stability of red pigments produced by an ednophytic fungus from Ginkgo biloba L

Fungal pigments are a potential resource for natural food colorant.A strain of ednophytic fungus Penicillium purpurogenum SX01,which is able to produce abundant soluble red pigments was isolated from the twigs of Ginkgo biloba L.This strain was cultured with PDA liquid medium,its extracellular water-soluble red pinments were extracted by Centrifugation and filtration.The stability of this pigments under different conditions such as,illumination,pH,temperature and mental ion were studied by analyzing its specific absorbance.The results showed that this pigments were sensitive to white-light and temperature.It was stable under 60℃,but not stable over 80℃.This pigments is very sensitive to the sunlight,its color value dropped significantly under prolonged sun exposure.The pigment was stable for different pH,and color value of the extracting solution was even higher at the pH10.This pigments were less affected by metal ions;while the color value was increased with Zn2+;Cu2+、Al3+ had almost no influence;Fe2+ 和Fe3+had some negative effect.