Quick spectrophotometric identification of synthetic food colorants by linear regression analysis

Abstract

A quick spectrophotometric method for the identification of artificial food colorants, following isolation by adsorption on wool, is described. The method is based on a computational comparison of a measured UV/VIS colorant spectrum with a series of reference spectra. A calculated spectrum, which shows the best fit to the measured spectrum, is obtained from the reference spectra by means of linear regression analysis. The food colorants present in the sample are obtained from the calculation parameters of the linear regression analysis. The method is tested with mixtures of pure food colorants and selected artificially coloured foodstuffs. Agreement between measured and calculated spectra was excellent in most cases. All colorants present could be unambiguously identified.

Determination of Carmoisine, Allura red and Ponceau 4R in sweets and soft drinks by Differential Pulse Polarography

“…Moreover, it is impossible to distinguish easily between synthetic and natural dyes. In order to solve these difficulties, mathematical treatments of the spectra have been proposed (Saguy et al, 1978;Hofer and Jenewein, 1997;Capitan-Vallvey et al, 1998;Berzas Nevado et al, 1999a, b). Several recent papers demonstrate the interest of the UV-visible spectrometry (Kiroglu and Ozdemir, 2000;Capitan Vallvey, 2002;Altinoz and Toptan, 2003;Koyuncu et al, 2003).…”

Liquid Chromatographic Determination of Natural and Synthetic Colorants in Lyophilized Foods Using an Automatic Solid-Phase Extraction System

“…Polygosyl-bonded silica reversedphase sorbent with octadecyl functional groups (RP-C18) was obtained from Sigma-Aldrich. Natural cotton was washed with petroleum ether to eliminate the natural grease of the fiber (24).…”

Investigations of In vitro Digestibility of Proteins Bound to Food Colors

“…Colors play a very prominent role in modulating the appearance and overall quality perception of the processed foods for selection of the product by the consumers. Colorants are also used to attract the attention of a particular age group of the consumers, especially in case of the children for indicating their choice of foods [1]. Food colorants have a long history of their use all over the world in raw and processed foods, although their use in food is still controversial in view of their adverse effects on health [2].…”