Which of the following procedures is suitable for identifying the food colouring added to a pastry sample?

The suitable procedure for identifying the food coloring added to a pastry sample is to do a chromatogram of the coloring extract. Chromatography is a technique that separates and identifies the components of a mixture. In this case, a small amount of the coloring extract can be applied to a special paper, and then a solvent is used to separate the components of the extract. The different components will travel at different speeds, allowing for the identification of the specific food coloring used in the pastry sample. This method is more specific and reliable compared to the other options provided, such as carrying out some food tests or examining the pastry sample under a microscope, which may not provide conclusive results. Determining the molar mass of the coloring is also not a suitable method for identifying the food coloring added to the pastry sample.