| 摘要 |
PURPOSE: Nano-sized mixture containing edible pigments is provided, which has no harm to human body, thermal stability, and brilliant color by using edible pigments and layered metal hydroxides. CONSTITUTION: Nano-sized mixture containing edible pigments is prepared by coprecipitating layered metal hydroxides such as hydroxy double salts(HDS), or layered double hydroxides(LDHs) and edible pigments having anions, wherein the concentration of metal ions is 0.01-5M, the concentration of edible pigments is 0.1-10times higher than total metals, the pH of the solution is 4-11, the reaction temperature is 0-50deg.C, and the solvent is water, alcohol or mixture thereof. The hydroxy double salts(HDS) have a crystalline structure of hydrozincite(Zn5(OH)6(CO3)2·nH2O) or zinc basic salts(Zn5(OH)8Cl2·nH2O). The layered double hydroxides(LDHs) are expressed by a formula of £M(II)1-xM(III)x(OH2)|¬x+ (A¬n- x/n)·mH2O, wherein M(II) is Zn+2, Mg+2, Ca+2 or Fe+2, M(III) is Al+3, Fe+3, Cr+3 or Co+3, and A is anion. The edible pigment is Red #40, Yellow #5, blue #1, red(#2, #102, #106), green #3, blue #2, etc., preferably Red #40, Yellow #5 or blue #1.
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