Spectroscopic Analysis of Food Dyes: Ensuring Colour Consistency

In this webinar we will demonstrate the ability to assess a material’s colour using UV-Visible instrumentation. These analyses consist of determining the colour of multiple food dye samples, as well as how to determine the colour difference between samples.

The United States FDA outlines a list of dyes and alternative pigments which are acceptable for use in food products. As this list is subject to change, some commonly used dyes, like FD&C 3, are being listed as unusable and must be replaced with an acceptable dye within a specified timeframe.

This can be a huge challenge. For one colour, there can be many alternative pigments, making it harder to select the best replacement dye. To retain the same appearance for a given colour, these new dyes must be vetted and demonstrate minimal difference in appearance. Consequently, a robust method for ensuring the colour of the new system is indistinguishable from the old pigment is needed.

In this webinar, we will show you how UV-Visible absorption measurements can be used to demonstrate colour analysis process as well as methods of comparison between different red pigments, such as FD&C 3. We will also outline how to determine the optimal conditions to mimic the colour of FD&C 3 through these analyses, indicating how UV-Visible instrumentation can be used to ensure a consistent colour between products when using different dyes.

We will cover:

• How, as the colour of these pigments is observable by eye, these compounds can readily be analysed using UV-Visible techniques.
• How using the measured absorption spectrum of these dyes, the colour of these samples can be ascertained without bias.
• And how the colour difference between two samples can be gleaned, providing a method for assessing how close a replacement dye is to the original pigment.

Key learning points:

• Learn how to determine commonly used colour values through UV-Visible measurements.
• Gain insights into UV-Visible analyses of various sample types (e.g. powders vs liquids).
• Understand methods for determining the best colour match between food dyes.

Presenter: Jennifer Empey-Kohl (Applications Scientist, Thermo Fisher Scientific)

Jennifer Empey-Kohl has been with Thermo Fisher Scientific as an Applications Scientist for 3 years where she supports cuvette-based UV-Visible instruments. Prior to this position, she received her PhD in Chemistry from The Ohio State University where she used various spectroscopic techniques to study colloidal nanoparticles.