| Name | Acorn shell btown |
| Synonyms | Acorn shell btown xiang zi ke brown |
| Molecular Formula | C25H32O13 |
| Physical and Chemical Properties | Chemical nature dark brown powder. Easily soluble in water and ethanol aqueous solution, insoluble in non-polar solvents. It is brown under alkaline conditions and reddish brown under acidic conditions. Stable to both heat and light. |
| Use | Use as food and feed colorants, China's provisions can be used for cola drinks and wine, the maximum use of 1.0 g/kg and 0.3 g/kg. |
1. break the acorn shell (separate the shell kernel), wash with water to remove impurities easily soluble in water, and then treat with 1%-1.5% hydrochloric acid (solid-liquid ratio 1:20) to remove tannin, protein, starch, etc., and then heat and extract pigment with dilute alkali solution (PH9-11). Ethanol is added to the extract (the concentration of ethanol is controlled at 5%-10%) to remove residual colloidal starch and other impurities by precipitation. After centrifugal separation, ethanol is recovered, and finally the pigment liquid is concentrated, sprayed and dried to obtain the product.
2, obtained by extracting acorn shells with water, filtering, purifying and refining.