Doneness indicators, e.g. to indicate whether the food is cooked

Full Title

Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents > for packaging foodstuffs or other articles intended to be cooked or heated within > Cooking or heating method specially adapted to the contents of the package > Doneness indicators, e.g. to indicate whether the food is cooked