How to contain the smell of truffle spice?
I make tiny pouches, sousvide and then store them in a vacuum container. It works well. Takes some time to do but when you make tiny portions the rest will stay very fresh .In case you have some left in the little pouch you can put it in a small bottle with a good olive oil and use as a dressing over fried eggs or mushrooms or veg or potatoes or a deli salad...your choice. Vacuum containers are very handy since you can reuse them every time and everything stays perfect. 
I even put them in the freezer myself and the freezer does not smell at all.