Reactive Dyes 2

Development of Detection Methods for Bifunctional Reactive Dyes and Other Unauthorized Pigments in Food

Projektstatus

Abgeschlossen

Projektlaufzeit

01.05.2022

- 01.12.2024

Ansprechpartner

Andreas Juadjur

Ausgangslage

Reactive dyes are highly valued in the textile industry for their brilliant color and excellent colorfastness, which they achieve through chemical bonding to the textile fiber via so-called reactive anchors. While cotton or wool fibers serve as binding partners in textiles, in food products, numerous ingredients—such as proteins, starch, maltodextrins, pectins, and many others—can act as reaction partners. Especially when present in bound form, these substances cannot be detected using standard analytical methods, meaning that adulteration may not initially be apparent through analysis.

Projektbeschreibung

Food coloring is important in many product categories. Since artificial colors are controversial from a health perspective and natural colors often have technological and economic drawbacks, reactive dyes derived from fruit pigment extracts are gaining attention. In the predecessor project (AiF 19637 N), methods were already developed for the detection of reactive dyes with reactive anchor groups in spice extracts, fruit concentrates, and meat and sausage products. This follow-up project extends this analytical approach to applications that have been difficult to detect thus far, particularly bifunctional reactive dyes with anchor groups on both sides of the azo group. A rapid photometric method is being expanded to include additional dye classes and shades; to this end, a screening is underway with 345 reference samples, including 112 reactive dyes. In addition, an NMR database for the unambiguous identification of prohibited colorants is being expanded. Furthermore, the detection of characteristic pyrolysis products following enrichment via TED-GC-MS is being evaluated to cover various food matrices.