You Should Never
Cheeses like Brie, blue, goat, ricotta, and mozzarella are apt to mold in an airless environment.
Raw Onions and Garlic
Vacuum-sealed onions and garlic spoil faster than if you’d never sealed them at all.
These vegetables include cabbage, broccoli, kale, radishes, bok choy, cauliflower, Brussels sprouts, and arugula. To safely vacuum seal them, you first have to blanch them and let them cool thoroughly.
Cooked mushrooms, however, are fine to vacuum seal.
One way to avoid their rapid decay is to freeze them first. Once frozen, you can safely vacuum seal bananas in that preserved state.