In the kitchen, many food ingredients are “roasted”, i.e., thermally processed without addition of a liquid. The most common are coffee, chocolate, nuts, almonds, flour and spices. In the coffee industry, roasting is performed by putting the seeds in a heated vessel at temperatures between 160 °C and 250 °C for a time between 8 and 20 min, depending on the final desired organoleptic properties. Based on the phenomena triggered by heat, the roasting process can be divided into five steps: drying, yellowing, first crack, development and second crack. The two first steps are important for roasting, as if an insufficient quantity of water is released, the external part will roast correctly, but the inside of the seeds will remain “raw”, with an undesirable bitter flavor. Colour changes are the most obvious change in seeds during roasting. In large-scale industrial applications, the roasting degree is even evaluated through the colour changes.