Carotenoids are the compounds responsible for yellow, orange and red colours in many fruit, vegetable and algal sources. Within each source, carotenoids vary in concentration, proportions and chemical structure, all of which influence how it can be used in a food product.
When heat is added to a substance, the molecules and atoms vibrate faster. As atoms vibrate faster, the space between atoms increases. The motion and spacing of the particles determines the state of matter of the substance. The end result of increased molecular motion is that the object expands and takes up more space.
Gases can fill a container of any size or shape. It doesn't matter how big the container is. The molecules spread out to fill the whole space equally. Think about a balloon. No matter what shape you make the balloon, it will be evenly filled with the gas molecules. Even if you make a balloon animal, the molecules are spread equally throughout the entire shape. Liquids can only fill the bottom of a container, while gases can fill it entirely.