DBPapers
DOI: 10.5593/SGEM2014/B52/S20.048

INFLUENCE OF ADDITIVES ON ABSORPTION SPECTRA OF FOOD DYE CI FOOD BLUE 5 AND ITS DETERMINATION IN FOOD PRODUCTS

M. Miljkovic, V. Rakic, V. Miljkovic, B. Arsic
Wednesday 1 October 2014 by Libadmin2014

References: 14th International Multidisciplinary Scientific GeoConference SGEM 2014, www.sgem.org, SGEM2014 Conference Proceedings, ISBN 978-619-7105-18-6 / ISSN 1314-2704, June 19-25, 2014, Book 5, Vol. 2, 359-366 pp

ABSTRACT
With the aim to use additives in food and health protection of consumers, JECFA
develops the concept of acceptable daily intake (ADI). The definition of ADI for
additives is based on the proposition of Zehman and Fitzugh (1954). Synthetic food dyes are standardized chemicals with standardized dye strength.
Food Blue 5 (C.I.N042051), Sulphan Blue, is chemically calcium or sodium salt [4-[a- (4-diethylaminophenyl)-5-hydroxy-2,4-disulfophenylmethyliden]2,5-cyclohexadien-1- yliden] diethyl ammonium-hydroxide of intrinsic salt. Three methods were used for the qualitative proving of the investigated dye in products. The first method relies on the reaction of dye with 3 M sodium hydroxide solutions and conc. hydrochloric acid. The investigated blue dye was discolored upon the addition of the reagent, which proves the dye. The second method relies on the determination of retention factor (Rf) using paper chromatography. It was found that Rf = 0.94 for the investigated dye sample (Rf = 0.96 corresponds to standard sample). The third method is the determination of the absorption maximum in visible spectrum, max = 638 nm. In order to investigate whether particular additives often found in food cause change of chromophores influence in dye molecule and change of its molar absorptive coefficient, it was performed the investigation of influence (vitamin C, citric acid, aspartame) on spectroscopic characteristics of Food Blue 5 using VIS spectrophotometric analysis (350-700 nm). Vitamin C as an additive was confirmed in measurements that does not affect changes neither in intensity of maximum of absorption of dye Food Blue 5, nor in its position. Citric acid leads to changes in intensity of absorption maximum; lower concentrations increase the intensity of absorption maximum to a greater extent. It was determined that 48 h staying of dye Food Blue 5 solution with citric acid gives as a result loss of absorption maximum (max= 638 nm), and colors of solutions afterwards were lost. It can be concluded that citric acid causes the degradation of chromophore part in dye molecule. In measurements, aspartame does not cause neither change in intensity of absorption maximum in dye Food Blue 5 nor changes in its position. The value of molar absorption coefficient of dye Food Blue 5 was calculated on wavelength = 638 nm; it is =22975.42 dm3/mol∙cm. The calculated value is necessary for the quantitative spectrophotometric determination of dye Food Blue 5.

Keywords: Patent Blue V, vitamin C, aspartame, citric acid