Rapid UV/Vis Spectroscopic Dye Authentication Assay for the Determination and Classification of Reactive Dyes, Pigments, and Natural Dyes in Coloring Foodstuff.

Food authenticity in the field of food dyes can be interpreted as the correctness of the coloring ingredients indicated. The Rapid UV/vis Spectroscopic Dye Authentication Assay (RaSDAY) presented in this work was used to verify the authenticity of water-soluble reddish colorings for food use. RaSDAY includes the processing of samples under different experimental conditions with pH variations and heat exposure. The absorbances measured are analyzed by principal component analysis and a -nearest neighbors algorithm. As a result, classification of anthocyanins, betalains, and carmine and the detection of pigments, undeclared artificial food dyes, and reactive textile azo dyes can be performed by utilizing a rapid screening method. In 17 out of 20 samples of coloring food additives that were included in this work, reactive dyes, unpermitted pigments, and artificial food dyes were detected using the developed method. "Reactive Red 120", "Reactive Red 195", and "Reactive Red 198" were identified by subsequent H NMR spectroscopy in eight of those samples.