Synthetic food colorants in soft drinks from the Romanian market

Water soluble synthetic food colorants are widely used in the production of beverages for improving their appearance, being highly appreciated by producers especially due to their stability, compatibility with the food matrix, tinctorial power and price. However, previous studies on the toxicity of these food additives highlighted several worrying health-related issues on consumers: an excessive consumption of certain synthetic food colorants can cause allergic reactions, attention deficit hyperactivity disorder (ADHD) in sensitive children, or even cancer. Because soft drinks are highly-consumed beverages amongst all age groups, especially teenagers and children, they can be considered as a health risk for consumers. The aim of the present work is provide data on the content of eight synthetic food colorants from several soft drinks available on the Romanian market: Allura Red (E 129), Azorubine (E 122), Brilliant Blue (E 133), Patent Blue (E 131), Ponceau 4R (E 124), Ponceau 6R (E 126), Tartrazine (E 102) and Sunset Yellow (E 110). Soft drinks were purchased from hypermarkets; representative samples were subjected to solid phase extraction (carbonated soft drinks were degassed on an ultrasonic bath before extraction), then filtered through 0.45 μm membrane filters. Analytical determinations were performed by high performance liquid chromatography (HPLC) on an Agilent 1100 system equipped with an diode array detector (DAD), separations being accomplished on a C18 column, using gradient elution with ammonium acetate buffer and acetonitrile as the mobile phase The HPLC method was optimized and validated, using multiple-specific wavelengths in the visible range to monitor the analytes to provide the highest sensitivity and specificity. The HPLC-DAD developed method proved to be fast (less than 20 minutes run-time), sensitive and accurate and suitable for the routine analysis of soft drinks containing a broad range of colorants. The obtained results showed that: 1) in certain products, besides the declared colorants of the label, several undeclared ones were found; 2) food colorants were generally added in low and rather safe amounts, all samples revealing colorants’ levels in conformity with Romanian and EU regulations.