First of all, the main purpose of vacuum pumping in the design of food packaging bag is to prevent the contact between air and food, slow down food oxidation, so as to avoid microbial growth and food deterioration. Whether to vacuum or not depends on the characteristics of food and the length of anti-corrosion time. Generally, the food that can be sold in a short time and should not be added with too many preservatives, such as cooked chicken feet and pig feet, and the packaging of some cereals is more suitable for vacuum pumping.

抽真空的食品包裝特別要注意的是抽真空并不能阻斷食物里面的細菌生長，只能對那些需要氧氣的微生物減緩的作用，要想食物不腐壞，延長保質期，就需要對食物進行滅菌處理，比如說使用高溫，紫外線燈光照射等等方式，然后在使用消毒鍋的食品包裝袋進行包裝抽真空，這樣就大大的延長了保質期。

Special attention should be paid to the food packaging of vacuum pumping. Vacuum pumping can not block the growth of bacteria in the food, but can only slow down the microorganisms that need oxygen. In order to prevent food from spoilage and prolong the shelf life, it is necessary to sterilize the food, such as high temperature, ultraviolet light irradiation and so on, Then vacuum the food packaging bag using the sterilizer, which greatly prolongs the shelf life.

另外我們在超市當中看到的一些包裝袋是鼓鼓的里面有氣體，這是另外一種防腐手段，采用的是給包裝袋沖入一些惰性氣體，例如常用的氮氣，二氧化碳等單一或者組合氣體，這種成本也比較低，多使用在膨化食品包裝當中，保持食品干燥，防止食物變質。

In addition, some of the packaging bags we see in the supermarket are bulging with gas inside. This is another anti-corrosion method. It uses to inject some inert gases into the packaging bags, such as common single or combined gases such as nitrogen and carbon dioxide. This kind of cost is also relatively low. It is mostly used in puffed food packaging to keep the food dry and prevent food deterioration.