E122 o Azorubina è un sale di sodio, un colorante alimentare comune, un colorante azoico e un ingrediente inserito nella lista degli additivi alimentari europei come colorante E122 e internazionalmente conosciuto come CI 14270.

A cosa serve e dove si usa

Cosmetica 

Ingrediente cosmetico soggetto a restrizioni  IV/19 come Voce pertinente negli allegati del regolamento europeo sui cosmetici n. 1223/2009. Sostanza o ingrediente segnalato: Disodium 4-hydroxy-3-[(4-sulphonatonaphthyl)azo]naphthalenesulphonate

Sicurezza

Per quanto riguarda la sicurezza alimentare, l'EFSA (European Food Safety Authority) ha concluso che il componente, pur rilevando un aumento di iperattività nei bambini di 3, 8 e 9 anni, non ha rivelato alcun segno di genotossicità (1).

Nel Maggio del 2010 la FSA (Food Standard Agency) ha stabilito le linee guida per alcuni coloranti, tra i quali l'E122: "When using the colours listed below in food and drink there is a requirement (subject to a limited number of exemptions) to include the additional information that „name or E number of the colour(s)‟: may have an adverse effect on activity and attention in children" (2).

Il problema legato ai coloranti azoici (monoazo o diazo) è la degradazione fotocatalitica che porta ad un'eventuale ossidazione ed alla successiva formazione di impurità come le ammine aromatiche alcune delle quali svolgono attività cancerogena (3).

Molecular Formula    C₂₀H₁₂N₂Na₂O₇S₂

Molecular Weight    502.423 g/mol

CAS: 3567-69-9

EC number:  222-657-4

UNII    DR4641L47F

DTXSID3021225

Sinonimi : 

• E122
• Carmoisine
• CI 14270
• Acid red 14
• Acid Chrome Blue
• BA
• Acid Rubine
• Acid Brilliant
• Acid Fast Red FB
• Acetacid Red B

Bibliografia________________________________________________________________________

(1) numero Domanda: EFSA-Q-2008-226   Adottato: 24 Settembre 2009  Pubblicato: 12 novembre 2009

(2) EFSA - Guidance on the labelling of certain food colours as set out in Regulation 1333/2008

(3) Chung KT, Stevens SE Jr, Cerniglia CE. The reduction of azo dyes by the intestinal microflora. Crit Rev Microbiol. 1992;18(3):175-90. doi: 10.3109/10408419209114557.

Abstract. Azo dyes are widely used in the textile, printing, paper manufacturing, pharmaceutical, and food industries and also in research laboratories. When these compounds either inadvertently or by design enter the body through ingestion, they are metabolized to aromatic amines by intestinal microorganisms. Reductive enzymes in the liver can also catalyze the reductive cleavage of the azo linkage to produce aromatic amines. However, evidence indicates that the intestinal microbial azoreductase may be more important than the liver enzymes in azo reduction. In this article, we examine the significance of the capacity of intestinal bacteria to reduce azo dyes and the conditions of azo reduction. Many azo dyes, such as Acid Yellow, Amaranth, Azodisalicylate, Chicago Sky Blue, Congo Red, Direct Black 38, Direct Blue 6, Direct Blue 15, Direct Brown 95, Fast Yellow, Lithol Red, Methyl Orange, Methyl Red, Methyl Yellow, Naphthalene Fast Orange 2G, Neoprontosil, New Coccine, Orange II, Phenylazo-2-naphthol, Ponceau 3R, Ponceau SX, Red 2G, Red 10B, Salicylazosulphapyridine, Sunset Yellow, Tartrazine, and Trypan Blue, are included in this article. A wide variety of anaerobic bacteria isolated from caecal or fecal contents from experimental animals and humans have the ability to cleave the azo linkage(s) to produce aromatic amines. Azoreductase(s) catalyze these reactions and have been found to be oxygen sensitive and to require flavins for optimal activity. The azoreductase activity in a variety of intestinal preparations was affected by various dietary factors such as cellulose, proteins, fibers, antibiotics, or supplementation with live cultures of lactobacilli.