Why does the food packaging bag say "The bag is swollen and can't be eaten"?

Some foods are vacuum-packed, and inflated bags mean that air (and bacteria) will enter. It may accelerate the deterioration of food, so it is inedible.

Inflatable bags are divided into physical inflatable bags and bacterial inflatable bags. The former is mainly due to the vacuum degree in the bag can not meet the requirements when vacuum sealing, and the latter is due to the incomplete sterilization of bacteria and the proliferation of gas-producing bacteria in the product.

According to the common sense of physics, under normal circumstances, the air pressure in the packaged food bag should be the same as or lower than the outside after vacuum pumping. If the bag expands, it means that the air pressure in the bag is higher than the outside, which means that new gas is produced in the sealed packaging bag. These gases are metabolites produced by the proliferation of microorganisms, because a small amount of microbial metabolites is not enough to expand the bag.

Extended data:

The quality of food packaging bags in the flexible packaging industry, especially the hygienic quality, is directly related to food safety, so it is necessary to ensure that the raw materials and additives used meet the quality management system.

It is necessary to improve the industry and national standards for packaging film bags and strictly implement them, strengthen the inspection and supervision of food packaging, prevent unqualified food packaging from entering the market, and strengthen management to ensure the healthy development of the flexible packaging industry. The inspection items of food packaging single film bags are mainly divided into the following categories:

Appearance shall not have defects such as bubbles, perforations, waterlines, protruding ribs, poor plasticization, fish-eye stiffness, etc. The deviation of specification, width, length and thickness should be within the specified range. Physical and mechanical properties include tensile strength and elongation at break, which reflect the tensile ability of the product in use. If the project is unqualified, the food packaging bag is easy to break and be damaged during use.