and keep the food dry to prevent oxidation. Another thing is to make the bag look much better.
it will not be turbid when it is put into lime water, and the wooden strip with Mars will go out, — nitrogen and
if it can make the magnesium strip burn, it is nitrogen, and if it cannot, it is a rare gas.
first, nitrogen has stable chemical properties (but not inert gas), which can play an anti-corrosion role; Second, it can prevent fragile food (such as potato chips) from breaking during transportation