Studies On The Orange Pigments

The use of monascus pigments as food addictive has a long history. In the admixture of monascus pigments, orange pigments are the best fresh pigments, which is only prepared in a very small way in laboratory, and haven't been exploitaged and applied adequately. Because of its particular, striking colour and lustre, it is one of monascus pigments as is good for exploiture, and we can find out many productions which can be painted using orange pigments. Therefore, The systemic study about the exploiture of this monascus orange pigments, increase of the orange pigments yield and looking for the application scopes has a great significance both of theoretic and praxis.Firstly, the fermentation conditions of orange pigments produced by monascus were studied, and the optimize compositions of culture medium was determined based on single factor experiments and the orthogonal experimental design. The optimized culture as follows (g/L): cornstarch, 60.0; ammonium sulfate, 4.0; KH2PO4, 2.0; K2HPO4, 2.0; MgSO4·7H2O, 0.5; CaCl2, 0.1; FeSO4·7H2O, 0.01; ZnSO4·7H2O, 0.01; MnSO4·H2O, 0.03; NaNO3, 2.0; initiative pH5.0; fermentation time, 4.0d. Then the technics conditions of submerged fermentation were researched and under the optimal conditions the liquid production of orange pigments was obtained at 71.7U/ mL of color value and 1.13 of color shade. it was discovered that a great deal of dissolve of oxygen is propitious to the production of orange pigments.The different preparation methods of orange pigments were studied. Direct spray drying of fermentation liquor turned to the production with color value 3862.07U/g and color shade 1.99. Second method: extraction by means of organic solvent and spray drying. By this method, we obtained the production with protein and other impurities in small amounts. Finally, needle crystal of orange pigments was prepared by TLC. It's turned out that the major constituent of the needle crystal is rubropunctatine past a series of detections, and the rubropunctatine content took up 85.93% of gross. We established the determination of rubropunctatine in monascus pigments by HPLC.The stability of orange pigments was detected. Orange pigment was stable to heating comparatively, not stable to light and stable in acid condition with its stability weakened in pH >5.7 which appeared the fall of absorbency and the excursing of maximal absorption apex; When Na2SO3 and H2O2 were added, the stability of the pigment was seriously affected, but not changed with NaCl and sucrose; The extent of reaction of orange pigment...