NITROGEN

That's not just any ordinary air puffing up potato chip bags: It's nitrogen. Oxygen can cause the potatoes to spoil and the oil to go rancid, while the humidity found in ambient air makes the chips go soggy. Instead, packages are filled with nitrogen gas to help the snacks stay fresh. "Nitrogen flushing" is a process whereby all the air is removed from the bag and replaced with nitrogen gas. Nitrogen has no effect on the taste of the food and does not react with it in the same way that oxygen does, which means the food stays fresher for longer.