Is Vacuum-packed Food Absolutely Safe?
Vacuum packaging reduces the oxygen content in the storage bag and prevents the spoilage of food, maintaining food's color, aroma and taste, and prolonging its shelf life. It is universally known that the mildew and rancidity of food are mainly caused by the activities of microbes that need oxygen to survive. Hence, vacuum packaging is to destroy their suitable living environment so as to stop food from spoiling through remove the oxygen in the bag.
As far as the form of packing is concerned, there is nothing wrong with vacuum packaging. However, its security is affected by a variety of conditions, including the nature of vacuum-packed food, the character of packaging material, the quality of printing material, the packaging technology and the temperature control in the process of transportation and sales environment. And the safety of food will be influenced if any parts are unqualified. For example, the air in vacuum bags used for preserving food with an irregular shape, like meat, vegetable and cooked food, is hard to be removed totally. It's no use exhausting the air if there are some anaerobic microorganisms, which is impossible to prevent food from spoilage. Unqualified packaging materials and technologies not only cannot play a protective role, but may cause food pollution. And non-food grade packaging printing may also contaminate food.
Therefore, when purchasing vacuum-packed food, we ought to refuse packaging with swelling, unpleasant smell and incomplete labels. And we can't take the flavor of food as the criterion. The overflow of food smell means that air leakage occurs in vacuum bags and bacteria can flow freely. Meanwhile, it's important for us to pay attention to the production date, shelf life and storage requirements of food. We had better eat the food we purchase as soon as possible instead of putting it in the refrigerator for a long time.
