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 k-nearest neighbors algorithm. As
a result, classification of anthocyanins, betalains, and carmine and
the detection of Monascus 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 Monascus 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 1H NMR spectroscopy in eight of those samples.