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.
Conduction transfers heat energy through one substance to another when they are in direct contact. The moving molecules of a warm material can increase the energy of the molecules in a cooler material. Since particles are closer together, solids conduct heat better than liquids or gases.