Bridged polynuclear chromium complexes of Research

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Bridged polynuclear chromium complexes Progress

And so on. Ferromagnetic coupling with a new oxalate -bridged Cu (Ⅱ) a Cr (I))-Cu (Ⅱ) trinuclear complexes [J]. Chemistry ,1994,52:171 -175 . ( continued on page 47 ) 1 Cao Yanping , etc. Stability of pumpkin yellow 4714 . Table 14 metal ions on the stability of pigment concentration Pumpkin A / mg · mL of a Mg. + AI. + Ca. Ten Cu. + Fe. +0.000.4350.4350.4350.4350.4350.100.5020.4900.5020.5050.4940.200.6990.5980.7960.5130.796 experimental results show that when the ion concentration is less than 0.1mg / ML, had little effect on the pigment , when the ion concentration of 0.2mg/mL when Caz +, Fe. A small amount of pigment can precipitate under acidic conditions , the precipitate dissolved . Therefore, the use of the pigment no special requirements on water quality , such as the use of high calcium foods , acidic conditions are suitable. 3 Conclusions (1) pumpkin yellow , light and strong , with strong antioxidant activity , commonly used food additive sucrose, citric acid , flavor, sodium benzoate , vitamin C , etc. on the pumpkin is almost no effect on yellow pigment in acid or No change in the color of weak alkaline medium , so it is a stable, ideal for wide application of natural pigments. But not when heated at high temperature often . (2 ) No requirements on the water quality of this pigment is suitable for high- calcium acidic food or drink. (3 ) The results showed that pumpkin extract the best conditions for yellow pigment : pH = 2 , 95 ethanol , 45 ℃ under the extraction 3h, the second extraction. (4 ) Pumpkin is rich in resources , easy storage , low cost, its color , natural color , taste sweet , both nutrition, pharmacology, coloring multiple functions. Therefore, yellow squash as a natural pigment , bright color, high safety , good stability, rich source , extraction method is simple, is an ideal natural food coloring ,[link widoczny dla zalogowanych], has great practical value for development.