| Name | BLACK BEAN RED |
| Synonyms | BLACK BEAN RED |
| Physical and Chemical Properties | Chemical properties dark red liquid or purplish red paste or powder, easy to absorb moisture. Soluble in water and dilute ethanol, insoluble in absolute ethanol, ether, acetone and grease. The aqueous solution is bright red under acidic conditions, reddish brown under neutral conditions, and dark reddish brown to blue purple under alkaline conditions. Good light resistance and heat resistance, natural color and strong coloring power. Sensitive to iron and lead ions. The oral LD50 of mice is> 10g/kg. |
| Use | Use 1, as a food colorant, China's provisions can be used for cakes on the color, the maximum amount of 0.8g/kg, in the candy in the general dosage of 0.4~0.6g/kg, in the soda, wine and other beverages in the general dosage of 0.5~0.8g/kg. 2, natural edible red pigment. |
1. black bean (Glyczne soja sieb.et.Zucc.) seed coat is extracted with dilute ethanol solution, concentrated and dried.
2. ethanol extraction
Sorting to remove moldy black beans, quickly washing away silt with clear water, taking out and drying, stirring and soaking black beans with 3 times the amount of 70% ethanol at room temperature for 6 hours, then filtering; The filtrate is distilled and concentrated under reduced pressure until precipitation (insoluble substances such as protein, fat and sugar) is no longer precipitated. After the residual liquid is cooled, centrifuged at a speed of 3000r /min for 15min; after standing and settling completely, filter to remove the residue to obtain transparent red pigment.
Clear water extraction
Sorting to remove moldy black beans, quickly washing away silt with clear water, taking out and drying; Stir and soak with 5 times of clear water at room temperature for 12h or keep warm and stir with 4 times of clear water at 80~85 ℃ for 0.5h; After filtration, the filtrate is concentrated under reduced pressure until no precipitation is generated, and the residual liquid is centrifuged at high speed (3000r /min) to obtain clear liquid, after standing and settling completely, filter the waste residue to obtain transparent red pigment.