Structure:
① amaranthin r = β-d-glucopyranosuronic acid
② betanine r = H.
Molecular formula: C24H26O 13N2.
Molecular weight: 550.48
Physical and chemical properties: purple paste or amorphous dry powder, easy to absorb moisture, soluble in water and dilute ethanol solution. When the pH value is less than 7, the solution is purplish red and clear, and it is insoluble in organic solvents such as anhydrous ethanol and petroleum ether. It has poor stability to light and heat, and metal ions such as copper and iron have negative effects on its stability. When the pH value is greater than 9.0, the solution of this product changes from purple to yellow.
Source and preparation method: The edible parts of amaranth were used as raw materials, and the concentrated solution was obtained by water extraction and ethanol refining. After drying, the purple-red dried powder product can be obtained.
Toxicological basis: (Toxicological test of West China University of Medical Sciences)
①LD50: the oral dose of rats is greater than 10g/kg(bw), mice 10.8g/kg(bw) (female) and mice12.6g/kg (bw) (male).
② Mutagenesis test: Ames test, bone marrow micronucleus test and mouse sperm aberration test, no mutagenicity was found.
Quality requirements: quality standard (GB1227-1991)
The pH value is 6.0~8.0
Absorption wavelength (λ max)/nm around 535 nm
Absorbance (535nm) ≥ 6.0
Loss on drying /% ≤ 10.0
Residue on ignition /% ≤35.0
As /% ≤ 0.0002
Heavy metal (calculated as Pb) /% ≤ 0.00 15
Usage and precautions: colorant. Natural amaranth is a natural pigment. Because of its poor stability to light and heat, it is generally suitable in acid medium. At the same time, long-term heating should be avoided. China's "Hygienic Standard for the Use of Food Additives" (GB 2760-1996) stipulates that it can be used in juice (flavored) drinks, carbonated drinks, mixed wine, candy, cakes, red and green silk, green plum, hawthorn products, canned dyed cherries (for decoration, not suitable for eating) and jelly, with the maximum dosage of 0.25.