Brilliant Blue (Food Color)

Properties

Melting point: 283 °C (decomp.)(lit.) Density: 0.65 Storage condition: 2-8°C Solubility: Soluble in water, 1 mg/mL Form: Fine crystalline powder Color Index: 42090 Color: Dark purple Water solubility: Soluble λmax: 406 nm, 625 nm Molar extinction coefficient: ≥10000 at 306-310nm in water ≥80000 at 627-631nm in water ≥9500 at 627-631nm in water Merck: 14,1373 Stability: Stable. Incompatible with strong oxidizing agents. InChIKey: SGHZXLIDFTYFHQ-UHFFFAOYSA-L SMILES: [Na+].[Na+].CCN(Cc1cccc(c1)S([O-])(=O)=O)c2ccc(cc2)C(=C3\C=C/C(C=C3)=N+Cc4cccc(c4)S([O-])(=O)=O)\c5ccccc5S([O-])(=O)=O LogP: -0.320 CAS No.: 3844-45-9

Description & Synthesis Method

Brilliant Blue, also known as Food Blue No.1, is a water-soluble non-azo colorant. It is a synthetic food color. It is synthesized by condensation and oxidation of o-sulfobenzaldehyde and N-ethyl-N-(3-sulfobenzyl)-aniline.

Assay

Determined by Method 2 in OT-15. Sample size: 1.8～1.9 g. Buffer solution prepared with 15g sodium bitartrate. 1 mL of 0.1 mol/L TiCl₃ corresponds to 0.03965 g of colorant.

Physical and Chemical Properties

Dark purple to bronze particles or powder with metallic luster, odorless. It has good light and heat resistance. Stable to citric acid, tartaric acid and alkali. Easily soluble in water (18.7g/100mL, 21°C). 0.05% neutral aqueous solution shows clear blue color. It appears cyan in weak acid and yellow in strong acid; it turns purple only when boiled with alkali. Soluble in ethanol (1.5g/100mL, 95% ethanol, 21°C). Also soluble in glycerol and propylene glycol. It can be mixed with tartrazine to form green colorant.

Applications

It is a widely used blue food colorant. Used for coloring pastries, candies, cool beverages, bean paste and other products. It can be used alone or blended with other colorants to obtain black, adzuki bean, chocolate and other colors due to strong tinting strength. The typical dosage in food is low.

It serves as colorant for food, pharmaceutical preparations and cosmetics. It can also be used as colorant for feed. In China, the maximum usage level is 0.10 g/kg for red-green shredded decoration; 0.025 g/kg for fruit-flavored drinks, carbonated drinks, compound wine, candies, decorative icing on pastries, decorated canned cherries, green plums, shrimp chips and ice cream.

It can be used for calibration and standardization of testing methods for synthetic colorants in food, and as working standard for routine analysis and testing.

Production Method

Brilliant Blue is obtained by condensation of o-sulfobenzaldehyde and α-(N-ethylanilino)-m-toluenesulfonic acid in acidic medium to form leuco compound. Then oxidized by sodium dichromate or lead dioxide to form color pigment. After neutralization, salt out with sodium sulfate, then purify. For production of Brilliant Blue Aluminum Lake: prepare aluminum hydroxide from aluminum salts such as aluminum chloride and aluminum sulfate with alkalis like sodium carbonate, then add into Brilliant Blue aqueous solution for precipitation to get the product.