system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why, when you buy cakes from the Costco, Market Basket, etc. bakeries, they have ingredients like propylene glycol, caramel color, xantham gum, etc., that I would never use in a cake? Do they have vats of that stuff to bake cakes with?
gpt
Most of those additives are to preserve the cake so it can sit out for several days without tasting too stale, or to keep it from drying out. Artificial colors have obvious uses.

Vats? No, just bottles/cans like you would expect other ingredients to come in.